It could be argued that following Apple's purchase of Quattro and Google's of AdMob in late 2009/early 2010, we're now experiencing the inflation of the second mobile advertising bubble.

The founders of Quattro left Apple to set up session M, raising $6.5 million in May, while the founders of AdMob set up MoPub.

It's just completed its Series A funding round, raising $6.5 million. Seed investors Accel Partners and Harrison Metal doubled their previous investment in the company.

As part of the deal, Accel Partners' Rich Wong will join the board.

"MoPub is part of a new wave of mobile ads companies that are moving the industry forward very rapidly. 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 monetisation company," he said.

Scaling up

Launched in February 2011, MoPub claims over 250 publishers are signed up, with that number doubling each quarter. It hosted over 1 billion adverts in June.

It enables publishers to book and manage mobile rich media interstitials, banners and custom formats, whether on a direct sold basis or brokered through a network for apps and mobile websites across iOS, Android and mobile web.

"We are seeing massive user adoption in mobile but the monetisation is still a huge pain for everyone. It's nearly impossible for advertisers to reach the audiences that they want at scale today," said CEO Jim Payne.

"We're building a very high capacity ad serving platform to address this and take advantage of the new opportunities presented by mobile formats."

Currently with a staff of 12, which is expected to double by the end of 2011, MoPub is headquartered in San Francisco with a sales office in New York.

[source: MoPub]