Sec Form 4 Filing - Columbia Capital IV, LLC @ Millennial Media Inc. - 2012-10-29

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 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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1. Name and Address of Reporting Person Columbia Capital IV, LLC 2. Issuer Name and Ticker or Trading Symbol Millennial Media Inc. [ MM] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O COLUMBIA CAPITAL, 201 N. UNION STREET, SUITE 300 3. Date of Earliest Transaction (MM/DD/YY) 10/29/2012 (Street) ALEXANDRIA, VA22314 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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) Code V Amount (A) or (D) Price Common Stock 10/29/2012 S 2,202,329 ( 1 ) D $ 13.4425 11,297,902 ( 2 ) I By Funds ( 3 )

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 Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Columbia Capital IV, LLC C/O COLUMBIA CAPITAL 201 N. UNION STREET, SUITE 300 ALEXANDRIA, VA22314 X Columbia Capital Employee Investors IV, L.P. C/O COLUMBIA CAPITAL 201 N. UNION STREET, SUITE 300 ALEXANDRIA, VA22314 X COLUMBIA CAPITAL EQUITY PARTNERS IV QP L P C/O COLUMBIA CAPITAL 201 N. UNION STREET, SUITE 300 ALEXANDRIA, VA22314 X COLUMBIA CAPITAL EQUITY PARTNERS IV QPCO L P C/O COLUMBIA CAPITAL 201 N. UNION STREET, SUITE 300 ALEXANDRIA, VA22314 X Columbia Capital Equity Partners IV, L.P. C/O COLUMBIA CAPITAL 201 N. UNION STREET, SUITE 300 ALEXANDRIA, VA22314 X Signatures /s/ Donald A. Doering, Executive Vice President of Columbia Capital IV, LLC 10/29/2012 Signature of Reporting Person Date /s/ Donald A. Doering, Executive Vice President of Columbia Capital IV, LLC, the General Partner of Columbia Capital Employee Investors IV, L.P. 10/29/2012 Signature of Reporting Person Date /s/ Donald A. Doering, Executive Vice President of Columbia Capital IV, LLC, the General Partner of Columbia Capital Equity Partners IV, L.P., the General Partner of Columbia Capital Equity Partners IV (QP), L.P. 10/29/2012 Signature of Reporting Person Date /s/ Donald A. Doering, Executive Vice President of Columbia Capital IV, LLC, the General Partner of Columbia Capital Equity Partners IV, L.P., the General Partner of Columbia Capital Equity Partners IV (QPCO), L.P. 10/29/2012 Signature of Reporting Person Date /s/ Donald A. Doering, Executive Vice President of Columbia Capital IV, LLC, the General Partner of Columbia Capital Equity Partners IV, L.P. 10/29/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The total includes 1,947,092 shares sold by Columbia Capital Equity Partners IV (QP), L.P. ("CCIV (QP)"), 239,565 shares sold by Columbia Capital Equity Partners IV (QPCO), L.P. ("CCIV (QPCO)") and 15,672 shares sold by Columbia Capital Employee Investors IV, L.P. ("CCEI"). ( 2 )The total includes 9,988,544 shares held by CCIV (QP), 1,228,961 shares held by CCIV (QPCO) and 80,397 shares held by CCEI. ( 3 )Columbia Capital Equity Partners IV, L.P. ("CCEP") is the general partner of CCIV (QP) and CCIV (QPCO). Columbia Capital IV, LLC ("CC") is the general partner of CCEP and CCEI. Each of CCEP, CC and James B. Fleming, Jr., Harry F. Hopper III and R. Phillip Herget, III, who control CC, 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.

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 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).

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