Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Zachary George
  2. Issuer Name and Ticker or Trading Symbol
Millennial Media Inc. [MM]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director__X__ 10% Owner
_____ Officer (give title below)_____ Other (specify below)
(Last)
(First)
(Middle)
C/O CHARLES RIVER VENTURES, ONE BROADWAY, 15TH FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
10/29/2012
(Street)

CAMBRIDGE, MA 02142
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock 10/29/2012   S   1,690,498 (1) D $ 13.4425 8,672,214 (2) I By Funds (3)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares

Reporting Owners

Reporting Owner Name / AddressRelationships
 Director 10% Owner Officer Other
Zachary George
C/O CHARLES RIVER VENTURES
ONE BROADWAY, 15TH FLOOR
CAMBRIDGE, MA 02142
  X   X    

Signatures

 /s/ Brian F. Leaf, Attorney-in-fact  10/29/2012
**Signature of Reporting PersonDate

Explanation of Responses:

*If the form is filed by more than one reporting person, see Instruction 4(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).
(1)The total includes 1,644,344 shares sold by Charles River Partnership XIII, LP ("CRP XIII") and 46,154 shares sold by Charles River Friends XIII-A, LP ("CRF XIII-A").
(2)The total includes 8,435,447 shares held by CRP XIII and 236,767 shares held by CRF XIII-A.
(3)Charles River XIII GP, LP ("CR XIII GP, LP") is the general partner of CRP XIII. Charles River XIII GP, LLC ("CR XIII GP, LLC") is the general partner of both CRF XIII-A and Charles River XIII GP, LP. The reporting person is one of the managing members of CR XIII GP, LLC and does not have sole voting or dispositive power with respect to the reported securities. Each of CR XIII GP, LP, CR XIII GP, LLC, and the reporting person may be deemed to beneficially own the reported securities, but each disclaims beneficial ownership of such reported securities except to the extent of its or his pecuniary interest therein. The filing of this statement by any reporting person shall not be deemed an admission that such person is, for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise, the beneficial owner of any equity securities covered by this statement.

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