Rich media mobile ad network Greystripe has raised an extra $5.5 million to fund the creation of a unified ad platform.

Existing investor Incubic Venture Capital led the Series C funding with Steamboat Ventures and Monitor Ventures also participating.

The Greystripe board of directors also added Robert J. Majteles to its ranks. Mr. Majteles is founder of Treehouse Capital.

Greystripe intends to use this round of funding to integrate its mobile inventory directly into industry-accepted online media buying software, the San Francisco company said.

The integration will let advertising agencies click on a tab within the software to add mobile to the options. It will also allow Flash ads that are typically available only on the wired Internet to appear on the Apple iPhone.

A unified ad platform meshing both online and mobile will offer Web-like measurement such as engagement and eventually targeting based on location, Greystripe said.

Essentially, Greystripe's strategy is to grow mobile campaigns from online ad budgets.

The company cited a recent Jan. 16 to Feb. 6 Hewlett-Packard campaign where mobile was added to the media mix by checking a box for mobile. The mobile spend came out of HP's digital ad budget.

The HP campaign followed another rich media effort that Greystripe ran for Unilever's Axe deodorant brand which is claimed to have generated a 15 percent brand lift (see story). Mobile came out of Axe's online spend.

The Axe "Dirty Night Determinator" experience was created to support the launch of the Axe Detailer Shower Tool in Greystripe's iPhone network of apps.

Microsoft's Xbox and Dunlop Sports are also using mobile advertising network Greystripe's GS.Impact format with existing IAB medium rectangle Flash ads delivered to the mobile phones for the first time.

"Consistency in messaging is always a priority for any brand, and Axe is no different" said Shane Kent, shower brand manager for Axe, at the time. "At the onset of this campaign, we knew the original Flash ads were immensely successful in communicating the key messaging of the Detailer, while bringing the Axe brand to life.

"We did not want to lose the effectiveness of the ads at the cost of playing in a new channel, so it was important to us that the mobile ads have the same look and feel as the original Web-based ads, to provide the same rich experience to the consumer," he said.