Millenial Media is a mobile ad network company based in the U.S. that has raised $27.5 million. Bessemer Venture Partners, Columbia Capital, Charles River Ventures, and New Enterprise Associates (NEA) all participated in this round of funding. Millenial Media has raised a total of $65 million in funding thus far. Millenial Media raised this round of funding because the company wants to stay independent and not get acquired. They have plans to expand internationally too. [AllThingsD]

Millenial Media has released some numbers about the market share break-down between iOS, Android, RIM, Windows, and Symbian. Millenial is basing this on the ads that they distribute. Millenial’s ads reach about 63 million of the 77 million mobile web users in the U.S.

Millenial Media is a mobile ad network that competes with AdMob. AdMob was recently acquired by Google for $750 million in stock. Millenial Media is based in Baltimore, Maryland and raised $16 million in Series C for New Enterprise Associates, Bessemer Venture Partners, Columbia Capital, and Charles River Ventures.

Millenial will use the funding to help push the company past profitability, grow overseas, hire additional talent, and build more technology. Given that Google already spent a ton of money on a mobile ad network it seems uncertain what Millenial’s exit strategy will be.