X0306 4 2012-12-20 0001372375 Millennial Media Inc. MM 0001545621 Brandenburg John Christopher C/O MILLENNIAL MEDIA, INC. 2400 BOSTON STREET, SUITE 201 BALTIMORE MD 21224 0 1 0 0 EVP, Chief Technology Officer Common Stock 2012-12-20 4 F 0 834 13.26 D 3960093 D Common Stock 623848 I by GRAT The transaction reported represents the withholding of shares by the issuer to satisfy the reporting person's tax withholding obligations in connection with the non-reportable vesting and settlement of restricted stock units. This total includes 5,387 shares previously held by The John Christopher Brandenburg Grantor Retained Annuity Trust that were transferred to the reporting person on October 26, 2012 and are now owned directly by the reporting person. This total excludes the 5,387 shares transferred to the reporting person as described in footnote (2). The shares are held by The John Christopher Brandenburg Grantor Retained Annuity Trust, of which the reporting person is the trustee. Ho Shin, Attorney-in-fact 2012-12-26