Mobile ad company MoPub has raised $6.5 million in a Series A investment round, led by Accel Partners and joined by co-investor Harrison Metal Capital. Accel Partners was a seed investor for MoPub, a company founded by a former AdMob team member.  The ties are deep here, as AdMob’s breakthrough mobile ad platform was also an early investment for Accel Partners.

MoPub is an ad serving platform for mobile applications and websites, allowing mobile publishers to serve rich media banner and interstitial ads, optimizing their remnant inventory with networks.

“MoPub is part of a new wave of mobile ads companies that are moving the industry forward very rapidly,” said Rich Wong, Partner at Accel Partners.  “In a short time, they have put together a widely used product and an incredible team that I believe can build the next big mobile monetization company.”

This news comes on the heels of MoPub’s latest report showing rapid adoption by mobile publishers.  The company has been growing faster than expected, a contributing factor towards this latest round of funding.   Its offering is a mobile analogue to DoubleClick for Publishers (DFP) and AdMeld, which was recently purchased by Google in a $400MM transaction.  MoPub allows publishers to easily book and manage mobile rich media interstitials, banners and custom formats, whether on a direct-sale basis or brokered through a network.

Mobile advertising is truly showing its promise this week, as  Mojiva also closed a $25 million Series C round of funding. The round was led by Shamrock Capital Advisors, a leading investment firm dedicated to media, entertainment and communications sectors, with additional participation from Mojiva’s previous investors Pelion Venture Partners and Bertelsmann Digital Media Investments.

“Shamrock Capital has been one of the most successful private equity firms in the media segment and are backing top companies across all forms of media,” said Dave Gwozdz, CEO of Mojiva Inc. “Having investors with such a deep knowledge of the media space will be a huge benefit to us as we expand the business to meet the needs of brands who are increasingly relying on mobile as a critical advertising medium.”

Both MoPub and Mojiva take to a new level of advertising platforms.  From the usual online programs to mobile content, MoPub and Mojiva both seek to become influential engines in transitioning the advertising industry into the mobile realm.  MoPub provides mobile application publishers with the technology to mix advertising from a number of sources, including direct sales, networks, and promotional campaigns for the publishers’ other apps.  It’s open to any mobile publisher, and serves ads across Android, iOS and mobile web platforms.