Capital One will be appearing simultaneously in CityVille, FarmVille and The Pioneer Trail, starting this week - a first according to the companies. Players will be able to interact with the goat from Capital One's commercials, which is being introduced in both games as one the in-game incentives.

Increasingly brands are eying gaming as an alternative online promotion vehicle. This model was dramatically illustrated by Lada Gaga, and more lately, Best Buy. The retailer integrated the first retail branded store into Zynga's CityVille in a campaign that began Wednesday, August 31 and ended on September 6. Users were able to place a Best Buy store into their city to collect new products and unlock a limited edition decorative item.

Likely such participations are behind an interesting new eMarketer statistic just reported by Ad Age: Facebook ad revenue is growing fast, but its currency system, called "Credits," is growing even faster. The company will collect revenue of $470 million this year from Credits alone, up from $140 million in 2010.