Social ad network RadiumOne today announced that it has joined the exclusive group of approved platforms integrating with the Facebook Exchange.

Facebook has about 20 partners selling retargeting ads through FBX, a real-time bidding system where advertisers bid on each ad impression as it is served. RadiumOne’s distinction is its “ShareGraph,” which ranks, scores and evaluates social sharing connections across the web. The company offers sharing products, po.st, re.po.st and via.me, that help it create unique audience segments that take into account data beyond what happens directly on an advertiser’s website.

The Facebook Exchange is a key area of growth for Facebook and the companies that build upon it. Triggit, for example, just raised $7.4 million in large part because of FBX.

In a press release, RadiumOne CEO and founder Gurbaksh Chahal said, “FBX is one of the most meaningful innovations in the advertising space.”

eMarketer reported last week that overall RTB spending is expected to nearly double this year, and the maturation of the Facebook Exchange likely to be a key influence on future growth in the industry, which could reach more than $3.3 billion next year.