QIHU Qihoo 360 Technology Co. Ltd. American Depositary Shares, Every 2 of Which Representing Three Class A Ordinary Shares

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

o

Rule 13d-1(b)

o

Rule 13d-1(c)

x

Rule 13d-1(d)

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Highland Capital Partners VI Limited Partnership

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x (1)

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
—

6.

Shared Voting Power
12,839,920.5(2)

7.

Sole Dispositive Power
—

8.

Shared Dispositive Power
12,839,920.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
12,839,920.5

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
7.4%(3)

12.

Type of Reporting Person
PN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Highland Capital Partners VI-B Limited Partnership

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
—

6.

Shared Voting Power
7,039,258.5

7.

Sole Dispositive Power
—

8.

Shared Dispositive Power
7,039,258.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
7,039,258.5

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
4.1%

12.

Type of Reporting Person
PN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Highland Entrepreneurs’ Fund VI Limited Partnership

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
—

6.

Shared Voting Power
635,970

7.

Sole Dispositive Power
—

8.

Shared Dispositive Power
635,970

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
635,970

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
0.4%

12.

Type of Reporting Person
PN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

HEF VI Limited Partnership

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
—

6.

Shared Voting Power
635,970

7.

Sole Dispositive Power
—

8.

Shared Dispositive Power
635,970

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
635,970

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
0.4%

12.

Type of Reporting Person
PN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Highland Management Partners VI Limited Partnership

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
—

6.

Shared Voting Power
19,879,179

7.

Sole Dispositive Power
—

8.

Shared Dispositive Power
19,879,179

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
19,879,179

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
11.5%

12.

Type of Reporting Person
PN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Highland Management Partners VI, Inc.

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
—

6.

Shared Voting Power
20,515,149

7.

Sole Dispositive Power
—

8.

Shared Dispositive Power
20,515,149

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
20,515,149

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
11.8%

12.

Type of Reporting Person
CO

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Robert F. Higgins

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
United States of America

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
226,287

6.

Shared Voting Power
21,549,631.5

7.

Sole Dispositive Power
226,287

8.

Shared Dispositive Power
21,549,631.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
21,775,918.5

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
12.6%

12.

Type of Reporting Person
IN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Paul A. Maeder

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
United States of America

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
113,466

6.

Shared Voting Power
21,549,631.5

7.

Sole Dispositive Power
113,466

8.

Shared Dispositive Power
21,549,631.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
21,663,097.5

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
12.5%

12.

Type of Reporting Person
IN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Daniel J. Nova

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
United States of America

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
270,337.5

6.

Shared Voting Power
21,549,631.5

7.

Sole Dispositive Power
270,337.5

8.

Shared Dispositive Power
21,549,631.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
21,819,969

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
12.6%

12.

Type of Reporting Person
IN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Sean M. Dalton

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
United States of America

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
188,272.5

6.

Shared Voting Power
21,549,631.5

7.

Sole Dispositive Power
188,272.5

8.

Shared Dispositive Power
21,549,631.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
21,737,904

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
12.6%

12.

Type of Reporting Person
IN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Robert J. Davis

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
United States of America

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
69,997.5

6.

Shared Voting Power
21,549,631.5

7.

Sole Dispositive Power
69,997.5

8.

Shared Dispositive Power
21,549,631.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
21,619,629

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
12.5%

12.

Type of Reporting Person
IN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Fergal J. Mullen

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
Republic of Ireland

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
0

6.

Shared Voting Power
21,549,631.5

7.

Sole Dispositive Power
0

8.

Shared Dispositive Power
21,549,631.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
21,549,631.5

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
12.4%

12.

Type of Reporting Person
IN

CUSIP No. 74734M109

13G

1.

Name of Reporting Person
S.S. or I.R.S. Identification No. of Above Person

Corey M. Mulloy

2.

Check the Appropriate Box if a Member of a Group

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
United States of America

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
21,600

6.

Shared Voting Power
21,549,631.5

7.

Sole Dispositive Power
21,600

8.

Shared Dispositive Power
21,549,631.5

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
21,571,231.5

10.

Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares  o

11.

Percent of Class Represented by Amount in Row (9)
12.4%

12.

Type of Reporting Person
IN

CUSIP No. 74734M109

13G

Item 1(a)

Name of Issuer
Qihoo 360 Technology Co. Ltd.

Item 1(b)

Address of Issuer’s Principal Executive Offices
Block 1, Area D, Huitong Times Plaza
No. 71 Jianguo Rd, Chaoyang District
Beijing F4 100025

Item 2(a)

Name of Person Filing

This Statement on Schedule 13G is being filed on behalf of: (i) Highland Capital Partners VI Limited Partnership, a Delaware limited partnership (“Highland Capital VI”); (ii) Highland Capital Partners VI-B Limited Partnership, a Delaware limited partnership (“Highland Capital VI-B”); (iii) Highland Entrepreneurs’ Fund VI Limited Partnership, a Delaware limited partnership (“Highland Entrepreneurs’ Fund VI” and together with Highland Capital VI and Highland Capital VI-B, the “Highland VI Investing Entities”); (iv) HEF VI Limited Partnership, a Delaware limited partnership and general partner of Highland Entrepreneurs’ Fund VI (“HEF VI”); (v) Highland Management Partners VI Limited Partnership, a Delaware limited partnership and general partner of Highland Capital VI and Highland Capital VI-B (“HMP VI”); (vi) Highland Management Partners VI, Inc., a Delaware corporation and general partner of both HEF VI and HMP VI (“Highland Management”); and (vii) Robert F. Higgins (“Mr. Higgins”), Paul A. Maeder (“Mr. Maeder”), Daniel J. Nova (“Mr. Nova”), Sean M. Dalton (“Mr. Dalton”), Robert J. Davis (“Mr. Davis”), Fergal J. Mullen (“Mr. Mullen”), and Corey M. Mulloy (“Mr. Mulloy” and together with Mr. Higgins, Mr. Maeder, Mr. Nova, Mr. Dalton, Mr. Davis and Mr. Mullen, the “Managing Directors”), each of whom is a managing director of Highland Management, a limited partner of each of HMP VI and HEF VI, and a manager of Highland Management Partners VII LLC (“HMP VII LLC”), a Delaware limited liability company that is the sole general partner of Highland Management Partners VII Limited Partnership (“HMP VII”), a Delaware limited partnership that serves as the sole general partner of each of Highland Capital Partners VII Limited Partnership, a Delaware limited partnership (“Highland Capital VII”), Highland Capital Partners VII-B Limited Partnership, a Delaware limited partnership (“Highland Capital VII-B”), Highland Capital Partners VII-C Limited Partnership, a Delaware limited partnership (“Highland Capital VII-C”) and Highland Entrepreneurs’ Fund VII Limited Partnership, a Delaware limited partnership (“Highland Entrepreneurs’ Fund VII” and together with Highland Capital VII, Highland Capital VII-B and Highland Capital VII-C, the “Highland VII Investing Entities”).  Highland Management, as the general partner of the general partners of the Highland VI Investing Entities, may be deemed to have beneficial ownership of the shares held by the Highland VI Investing Entities.  The Managing Directors of Highland Management have shared power over all investment decisions of Highland Management and therefore may be deemed to share beneficial ownership of the shares held by Highland VI Investing Entities by virtue of their status as controlling persons of Highland Management.  Each Managing Director of Highland Management disclaims beneficial ownership of the shares held by the Highland VI Investing Entities, except to the extent

CUSIP No. 74734M109

13G

of each such Managing Director’s pecuniary interest therein.  Each of Highland Management, HMP VI and HEF VI disclaims beneficial ownership of the shares held by the Highland VI Investing Entities, except to the extent of each such entity’s pecuniary interest therein.   Each of the Managing Directors, in his capacity as a manager of HMP VII LLC, has shared power over all investment decisions of HMP VII LLC and therefore may be deemed to share beneficial ownership of the shares held by Highland VII Investing Entities by virtue of his status as a controlling person of HMP VII LLC.  Each of the Managing Directors disclaims beneficial ownership of the shares held by the Highland VII Investing Entities, except to the extent of each such Managing Director’s pecuniary interest therein.  The Reporting Persons expressly disclaim status as a group for purposes of this Schedule 13G.

Item 2(b)

Address of Principal Business Office
The address of each of the reporting persons is:

c/o Highland Capital Partners LLC

One Broadway, 16th Floor

Cambridge, Massachusetts

02142

Item 2(c)

Citizenship

Highland Capital VI

Delaware

Highland Capital VI-B

Delaware

Highland Entrepreneurs’ Fund VI

Delaware

HEF VI

Delaware

HMP VI

Delaware

Highland Management

Delaware

Mr. Higgins

United States of America

Mr. Maeder

United States of America

Mr. Nova

United States of America

Mr. Dalton

United States of America

Mr. Davis

United States of America

Mr. Mullen

Republic of Ireland

Mr. Mulloy

United States of America

Item 2(d)

Title of Class of Securities
Class A Ordinary Shares, $0.001 par value, of Qihoo 360 Technology Co. Ltd. (the “Shares”)

Item 2(e)

CUSIP Number
74734M109

Item 3

If this statement is filed pursuant to §§ 240.13d-1(b), or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

o

Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);

(b)

o

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

CUSIP No. 74734M109

13G

(c)

o

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);

(d)

o

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e)

o

An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);

(f)

o

An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);

(g)

o

A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G);

(h)

o

A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

o

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

o

Group, in accordance with §240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with

§240.13d-1(b)(1)(ii)(J), please specify the type of institution:____________________________.

Not applicable.

Item 4

Ownership

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a)

Amount beneficially owned:   

As of December 31, 2011, each of the following is the owner of record of the Shares set forth next to his or its name:

Highland Capital VI

12,839,920.5

Highland Capital VI-B

7,039,258.5

Highland Entrepreneurs’ Fund VI

635,970

HEF VI

0

HMP VI

0

Highland Management

0

Mr. Higgins

226,287

Mr. Maeder

113,466

Mr. Nova

270,337.5

Mr. Dalton

188,272.5

Mr. Davis

69,997.5

Mr. Mullen

0

Mr. Mulloy

21,600

CUSIP No. 74734M109

13G

As of December 31, 2011, Highland Capital VI was the record owner of and beneficially owned 12,839,920.5 Shares (the “HCVI Shares”) of the issuer. Highland Capital VI has the power to vote or direct the disposition of all of the HCVI Shares.  Such power is exercised through Highland Management as the sole general partner of HMP VI as the sole general partner of Highland Capital VI.

As of December 31, 2011, Highland Capital VI-B was the record owner of and beneficially owned 7,039,258.5 Shares (the “HCVI-B Shares” and together with the HCVI Shares, the “HC VI Shares”) of the issuer.  Highland Capital VI-B has the power to vote or direct the disposition of all of the HCVI-B Shares.  Such power is exercised through Highland Management as the sole general partner of HMP VI as the sole general partner of Highland Capital VI-B.

As of December 31, 2011, Highland Entrepreneurs’ Fund VI was the record owner of and beneficially owned 635,970 Shares (the “HEF VI Shares” and together with the HC VI Shares, the “H-VI Shares”) of the issuer.  Highland Entrepreneurs’ Fund VI has the power to vote or direct the disposition of all of the HEF VI Shares.  Such power is exercised through Highland Management as the sole general partner of HEF VI as the sole general partner of Highland Entrepreneurs’ Fund VI.

HMP VI, as the general partner of Highland Capital VI and Highland Capital VI-B, may be deemed to own the HCVI Shares beneficially and HEF VI, as the general partner of Highland Entrepreneurs’ VI Fund, may be deemed to own the HEF VI Shares beneficially.  Each of HMP VI and HEF VI disclaims beneficial ownership of the shares held by the Highland VI Investing Entities, except to the extent of each such entity’s pecuniary interest therein.

Highland Management, as the general partner of HMP VI and HEF VI, may be deemed to own the H-VI Shares beneficially.  The Managing Directors have the power over all investment decisions of Highland Management and therefore may be deemed to share beneficial ownership of the H-VI Shares by virtue of their status as controlling persons of Highland Management.  Highland Management and each of the Managing Directors disclaims beneficial ownership of the H-VI Shares, except to the extent of each such entity’s pecuniary interest therein.

Each of Messrs. Higgins, Maeder, Nova, Dalton, Davis, Mullen and Mulloy, as a manager of HMP VII LLC, may be deemed to beneficially own the Shares owned by the Highland VII Investing Entities, because they have power over investment decisions of HMP VII LLC, the sole general partner of the sole general partner of each of the Highland VII Investing Entities.  The Highland VII Investing Entities were the record and beneficial owners of an aggregate of 1,034,482.5 Shares on December 31, 2011, and such Shares are reflected above in the amount of Shares over which each of Messrs. Higgins, Maeder, Nova, Dalton, Davis, Mullen and Mulloy has shared voting or dispositive power.  Each of Messrs. Higgins, Maeder, Nova, Dalton, Davis, Mullen and Mulloy disclaims beneficial ownership of the Shares owned by the Highland VII Investing Entities, except to the extent of his pecuniary interest therein.

CUSIP No. 74734M109

13G

(b)

Percent of class:   

Highland Capital VI

7.4%

Highland Capital VI-B

4.1%

Highland Entrepreneurs’ Fund VI

0.4%

HEF VI

0.4%

HMP VI

11.5%

Highland Management

11.8%

Mr. Higgins

12.6%

Mr. Maeder

12.5%

Mr. Nova

12.6%

Mr. Dalton

12.6%

Mr. Davis

12.5%

Mr. Mullen

12.4%

Mr. Mulloy

12.4%

The percentages reported in this Schedule 13G are based upon 173,213,370 ordinary shares outstanding as of March 30, 2011 (according to a final prospectus on Form 424B4 filed by the issuer with the SEC on March 30, 2011).

(c)

Number of shares as to which the person has:

Number of Shares

Reporting Person

(i)

(ii)

(iii)

(iv)

Highland Capital VI

0

12,839,920.5

0

12,839,920.5

Highland Capital VI-B

0

7,039,258.5

0

7,039,258.5

Highland Entrepreneurs’ Fund VI

0

635,970

0

635,970

HEF VI

0

635,970

0

635,970

HMP VI

0

19,879,19

0

19,879,19

Highland Management

0

20,515,149

0

20,515,149

Mr. Higgins

226,287

21,549,631.5

226,287

21,549,631.5

Mr. Maeder

113,466

21,549,631.5

113,466

21,549,631.5

Mr. Nova

270,337.5

21,549,631.5

270,337.5

21,549,631.5

Mr. Dalton

188,272.5

21,549,631.5

188,272.5

21,549,631.5

Mr. Davis

69,997.5

21,549,631.5

69,997.5

21,549,631.5

Mr. Mullen

0

21,549,631.5

0

21,549,631.5

Mr. Mulloy

21,600

21,549,631.5

21,600

21,549,631.5

(i)

Sole power to vote or to direct the vote   

(ii)

Shared power to vote or to direct the vote    

(iii)

Sole power to dispose or to direct the disposition of   

(iv)

Shared power to dispose or to direct the disposition of   

CUSIP No. 74734M109

13G

Each of Highland Capital VI, Highland Capital VI-B, Highland Entrepreneurs’ Fund VI, HEF VI, HMP VI, Highland Management and the Managing Directors expressly disclaims beneficial ownership of any Shares, except to the extent of his or its pecuniary interest therein and any Shares held directly of record.

Item 5

Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following   o .

Item 6

Ownership of More than Five Percent on Behalf of Another Person

Not applicable.

Item 7

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company

Not applicable.

Item 8

Identification and Classification of Members of the Group

Each of the Reporting Persons expressly disclaims membership in a “Group” as defined in Rule 13d-1(b)(ii)(J).

Item 9

Notice of Dissolution of Group

Not applicable.

Item 10

Certification

Not applicable.  This Schedule 13G is not filed pursuant to Rule 13d-1(b) or Rule 13d-1(c).

CUSIP No. 74734M109

HIGHLAND CAPITAL PARTNERS VI LIMITED PARTNERSHIP

By:

Highland Management Partners VI Limited Partnership, its general partner

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

HIGHLAND CAPITAL PARTNERS VI-B LIMITED PARTNERSHIP

By:

Highland Management Partners VI Limited Partnership, its general partner

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

HIGHLAND ENTREPRENEURS’ FUND VI LIMITED PARTNERSHIP

By:

HEF VI Limited Partnership, its general partner

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

HEF VI LIMITED PARTNERSHIP

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

CUSIP No. 74734M109

HIGHLAND MANAGEMENT PARTNERS VI LIMITED PARTNERSHIP

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

HIGHLAND MANAGEMENT PARTNERSHIP VI, INC.

By:

/s/ Daniel J. Nova

Managing Director

/s/ Robert F. Higgins

Robert F. Higgins

/s/ Paul A. Maeder

Paul A. Maeder

/s/ Daniel J. Nova

Daniel J. Nova

/s/ Sean M. Dalton

Sean M. Dalton

/s/ Robert J. Davis

Robert J. Davis

/s/ Fergal J. Mullen

Fergal J. Mullen

/s/ Corey M. Mulloy

Corey M. Mulloy

CUSIP No. 74734M109

HIGHLAND CAPITAL PARTNERS VI LIMITED PARTNERSHIP

By:

Highland Management Partners VI Limited Partnership, its general partner

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

HIGHLAND CAPITAL PARTNERS VI-B LIMITED PARTNERSHIP

By:

Highland Management Partners VI Limited Partnership, its general partner

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

HIGHLAND ENTREPRENEURS’ FUND VI LIMITED PARTNERSHIP

By:

HEF VI Limited Partnership, its general partner

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

HEF VI LIMITED PARTNERSHIP

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

CUSIP No. 74734M109

HIGHLAND MANAGEMENT PARTNERS VI LIMITED PARTNERSHIP

By:

Highland Management Partners VI, Inc., its general partner

By:

/s/ Daniel J. Nova

Managing Director

HIGHLAND MANAGEMENT PARTNERSHIP VI, INC.

By:

/s/ Daniel J. Nova

Managing Director

/s/ Robert F. Higgins

Robert F. Higgins

/s/ Paul A. Maeder

Paul A. Maeder

/s/ Daniel J. Nova

Daniel J. Nova

/s/ Sean M. Dalton

Sean M. Dalton

/s/ Robert J. Davis

Robert J. Davis

/s/ Fergal J. Mullen

Fergal J. Mullen

/s/ Corey M. Mulloy

Corey M. Mulloy