Another day, another tweet acquisition. Although this time instead of buying out a third party tweet client, Twitter has assimulated an ad startup by the name of AdGrok.

When Twitter approached us and asked if we’d be interested in working on their monetization platform, we realized that this was a once-in-a-lifetime opportunity that we just couldn’t pass up. The fact that the Twitter team is both smart and user-focused only made our decision easier. (Official AdGrock Blog)

While Twitter already has a unique advertising platform, discovering new ways to monetize the tweet stream without offending users is increasing becoming difficult for the social network.

Instead of relying upon services like promoted trends to help keep the lights on, Twitter may use AdGrock to monetize users photo streams (in a similar way that TwitPic used AdSense to help generate almost $2 million in revenue in 2010).

With the social network hovering around 200 million users, AdGrock could help Twitter generate hundreds of millions of dollars (if not billions down the road), helping the service compete against Facebook as well as Google.

Neither AdGrock or Twitter have disclosed how much the social networking site paid to acquire the team, although for now it looks like everyone save AdGrock’s CEO will be working for Twitter.

Note: The CEO ironically defected towards Facebook, although according to TechCrunch there are no hard feelings between the founders and former CEO.