SEC FORM 3 SEC Form 3
FORM 3 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
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1. Name and Address of Reporting Person*
MAYFIELD XII A DELAWARE L P

(Last) (First) (Middle)
2484 SAND HILL ROAD

(Street)
MENLO PARK CA 94025

(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
04/01/2014
3. Issuer Name and Ticker or Trading Symbol
RUBICON PROJECT, INC. [ RUBI ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director X 10% Owner
Officer (give title below) Other (specify below)
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
Form filed by One Reporting Person
X Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock 97,000 D
Common Stock 1,500 I By Mayfield Associates Fund XII
Common Stock 1,500 I By Mayfield Principals Fund XII
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Series B Convertible Preferred Stock (1) (1) Common Stock 3,291,662 (1) D(2)(3)(4)
Series C Convertible Preferred Stock (1) (1) Common Stock 231,039 (1) D(2)(3)(4)
Series D Convertible Preferred Stock (1) (1) Common Stock 369,671 (1) D(2)(3)(4)
Series B Convertible Preferred Stock (1) (1) Common Stock 50,902 (1) I(2)(3)(4) By Mayfield Associates Fund XII
Series C Convertible Preferred Stock (1) (1) Common Stock 3,573 (1) I(2)(3)(4) By Mayfield Associates Fund XII
Series D Convertible Preferred Stock (1) (1) Common Stock 5,716 (1) I(2)(3)(4) By Mayfield Associates Fund XII
Series B Convertible Preferred Stock (1) (1) Common Stock 50,902 (1) I(2)(3)(4) By Mayfield Principals Fund XII
Series C Convertible Preferred Stock (1) (1) Common Stock 3,573 (1) I(2)(3)(4) By Mayfield Principals Fund XII
Series D Convertible Preferred Stock (1) (1) Common Stock 5,716 (1) I(2)(3)(4) By Mayfield Principals Fund XII
1. Name and Address of Reporting Person*
MAYFIELD XII A DELAWARE L P

(Last) (First) (Middle)
2484 SAND HILL ROAD

(Street)
MENLO PARK CA 94025

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Mayfield XII Management

(Last) (First) (Middle)
2484 SAND HILL ROAD

(Street)
MENLO PARK CA 94025

(City) (State) (Zip)
1. Name and Address of Reporting Person*
MAYFIELD ASSOCIATES FUND XII

(Last) (First) (Middle)
2484 SAND HILL ROAD

(Street)
MENLO PARK CA 94025

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Mayfield Principals Fund XII

(Last) (First) (Middle)
2484 SAND HILL ROAD

(Street)
MENLO PARK CA 94025

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Beck James T

(Last) (First) (Middle)
2484 SAND HILL ROAD

(Street)
MENLO PARK CA 94025

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Chaddha Navin

(Last) (First) (Middle)
2484 SAND HILL ROAD

(Street)
MENLO PARK CA 94025

(City) (State) (Zip)
1. Name and Address of Reporting Person*
VASAN ROBERT T

(Last) (First) (Middle)
2484 SAND HILL ROAD

(Street)
MENLO PARK CA 94025

(City) (State) (Zip)
Explanation of Responses:
1. The convertible preferred stock shall automatically convert into common stock on a one-for-two basis immediately prior to the completion of the Issuer's initial public offering of common stock and has no expiration date.
2. Mayfield XII Management, L.L.C. ("MF XII Management") is the sole general partner of each of Mayfield XII, a Delaware Limited Partnership ("MF XII") and Mayfield Associates Fund XII, a Delaware Limited Partnership ("MF A XII"), and is the sole managing director of Mayfield Principals Fund XII, a Delaware Multiple Series LLC ("MF PF XII"), and in such capacity may be deemed to beneficially own the shares of common stock beneficially held by each of MF XII, MF A XII and MF PF XII. MF XII Management is managed by three managing directors, James T. Beck, Navin Chaddha and Robert T. Vasan, and all action by the managing directors relating to the voting or disposition of the shares of common stock beneficially held by each of MF XII, MF A XII and MF PF XII requires approval of a majority of the managing directors.
3. Each of James T. Beck, Navin Chaddha, and Robert T. Vasan, as the managing directors of MF XII Management, may be deemed to share beneficial ownership of the shares that are beneficially owned by MF XII Management, but each disclaims such beneficial ownership, except to the extent of his pecuniary interest therein.
4. The filing of this statement shall not be deemed an admission that, for the purposes of Section 16 of the Securities Act of 1934 or otherwise, the Reporting Persons are the beneficial owners of equity securities covered by this statement.
Remarks:
Remarks: Exhibit List. Exhibit 24.1 - Power of Attorney. Exhibit 24.2 - Power of Attorney
James T. Beck, Authorized Signatory for Mayfield XII Management, L.L.C., the sole General Partner of Mayfield XII, a Delaware Limited Partnership 04/01/2014
James T. Beck, Authorized Signatory for Mayfield XII Management, L.L.C. 04/01/2014
James T. Beck, Authorized Signatory for Mayfield XII Management, L.L.C., the sole General Partner of Mayfield Associates Fund XII, a Delaware Limited Partnership 04/01/2014
James T. Beck, Authorized Signatory for Mayfield XII Management, L.L.C., the Managing Director of Mayfield Principals Fund XII, a Delaware Multiple Series LLC 04/01/2014
James T. Beck 04/01/2014
James T. Beck, Attorney-In-Fact for Navin Chaddha 04/01/2014
James T. Beck, Attorney-In-Fact for Robert T. Vasan 04/01/2014
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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POWER OF ATTORNEY  



Know all by these presents, that the undersigned hereby authorizes James T. 

Beck, for so long as he is an employee, member or partner of Mayfield, to 

execute for and on behalf of the undersigned, in the undersigned's 

individual capacity, in the undersigned's capacity as a member of any 

limited liability company and in the undersigned's capacity as a partner of 

any general or limited partnership, (i) any and all filings pursuant to 

Section 16 of the Securities Exchange Act of 1934 (the "Exchange Act"), 

including any and all Forms 3, 4 and 5, and Section 13 of the Exchange Act, 

including Schedules 13D and 13G, and any amendments thereto and joint 

filing agreements and other documents in connection therewith, and (ii) any 

applications for EDGAR access codes, including the Form ID, in each case as 

may be required to be filed from time to time with the U. S. Securities and 

Exchange Commission with respect to any investments of Mayfield Fund and 

its affiliates (collectively, "Mayfield"), and cause any and all of such 

forms, schedules, agreements and documents to be filed with the U. S. 

Securities and Exchange Commission pursuant to Section 13 and Section 16 of 

the Exchange Act, relating to the undersigned's direct or indirect
 

beneficial ownership of securities (in the undersigned's individual 

capacity, or in the undersigned's capacity as a member of any limited 

liability company or partner in any general or limited partnership).  The 

undersigned hereby grants to such attorney-in-fact full power and authority 

to do and perform any and every act and thing whatsoever requisite, 

necessary or proper to be done in the exercise of any of the rights and 

powers herein granted, as fully to all intents and purposes as the 

undersigned might or could do if personally present, with full power of 

substitution or revocation, hereby ratifying and confirming all that such 

attorney-in-fact, or such attorney-in-fact substitute or substitutes, shall 

lawfully do or cause to be done by virtue of this power of attorney and the 

rights and powers herein granted.  The undersigned acknowledges that the 

foregoing attorney-in-fact, in serving in such capacity at the request of 

the undersigned, is not assuming, nor is Mayfield assuming, any of the 

undersigned's responsibilities to comply with Section 16 or Section 13 of 

the Exchange Act.



This Power of Attorney shall remain in full force and effect until the 

undersigned is no longer an employee, member or partner of Mayfield, unless 

earlier revoked by the undersigned in a signed writing delivered to the 

foregoing attorney-in-fact.



IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be

executed as of this 31st day of January, 2011.









 /s/   

Name:  Navin Chaddha





 

POWER OF ATTORNEY  



Know all by these presents, that the undersigned hereby authorizes James T. 

Beck, for so long as he is an employee, member or partner of Mayfield, to 

execute for and on behalf of the undersigned, in the undersigned's 

individual capacity, in the undersigned's capacity as a member of any 

limited liability company and in the undersigned's capacity as a partner of 

any general or limited partnership, (i) any and all filings pursuant to 

Section 16 of the Securities Exchange Act of 1934 (the "Exchange Act"), 

including any and all Forms 3, 4 and 5, and Section 13 of the Exchange Act, 

including Schedules 13D and 13G, and any amendments thereto and joint 

filing agreements and other documents in connection therewith, and (ii) any 

applications for EDGAR access codes, including the Form ID, in each case as 

may be required to be filed from time to time with the U. S. Securities and 

Exchange Commission with respect to any investments of Mayfield Fund and 

its affiliates (collectively, "Mayfield"), and cause any and all of such 

forms, schedules, agreements and documents to be filed with the U. S. 

Securities and Exchange Commission pursuant to Section 13 and Section 16 of 

the Exchange Act, relating to the undersigned's direct or indirect
 

beneficial ownership of securities (in the undersigned's individual 

capacity, or in the undersigned's capacity as a member of any limited 

liability company or partner in any general or limited partnership).  The 

undersigned hereby grants to such attorney-in-fact full power and authority 

to do and perform any and every act and thing whatsoever requisite, 

necessary or proper to be done in the exercise of any of the rights and 

powers herein granted, as fully to all intents and purposes as the 

undersigned might or could do if personally present, with full power of 

substitution or revocation, hereby ratifying and confirming all that such 

attorney-in-fact, or such attorney-in-fact substitute or substitutes, shall 

lawfully do or cause to be done by virtue of this power of attorney and the 

rights and powers herein granted.  The undersigned acknowledges that the 

foregoing attorney-in-fact, in serving in such capacity at the request of 

the undersigned, is not assuming, nor is Mayfield assuming, any of the 

undersigned's responsibilities to comply with Section 16 or Section 13 of 

the Exchange Act.



This Power of Attorney shall remain in full force and effect until the 

undersigned is no longer an employee, member or partner of Mayfield, unless 

earlier revoked by the undersigned in a signed writing delivered to the 

foregoing attorney-in-fact.



IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be

executed as of this 31st day of January, 2011.









 /s/   

Name:  Robert T. Vasan