After just eight months of ownership, startup studio Science Inc. of Santa Monica announced yesterday that it had sold off its mobile advertising network PlayHaven to mobile game publisher RockYou of San Francisco for an undisclosed amount.

PlayHaven was added to Science’s portfolio last September when it was purchased from mobile analytics company Upsight of San Francisco. In recent months, PlayHaven has been independently operating out of its headquarters in San Francisco while Science was trying to acquire RockYou and pair the companies.

Those plans were reversed when RockYou indicated it would rather buy PlayHaven itself.

“In a world where you own mobile games, it’s great to own an ad network,” said Mike Jones, chief executive of Science. “When you have highly concentrated supply and demand partners in a mobile ad platform like PlayHaven, it’s really important to have owned-and-operated properties to balance out the swings (in advertising demand).”

Jones declined to say if Science gained a stake in RockYou from the sale, but said the game publisher’s business was “surprisingly large.” The PlayHaven sale represents Science’s first exit.

PlayHaven was Science’s only mobile gaming focused company in Science’s portfolio, but Jones said the startup studio would remain dedicated to other aspects of the mobile content industry. Science has stakes in several mobile focused companies including content aggregation website Delicious and lifestyle tips mobile app Inlight.

“We love that area. I think we’ll stay very narrowly focused on the daily habit and daily content themes. I don’t expect we’ll be buying games,” he said.

Technology reporter Garrett Reim can be reached at [email protected]. Follow him on Twitter @garrettreim for the latest in L.A. tech news.