Ad Tech Start-Up Sociomantic Labs Grabs Google’s Jason Kelly

Last December, Google bought ad tech company AdMeld for $400 million; in June, its CEO Michael Barrett left for Yahoo.

Now another top AdMeld employee is out: Jason Kelly, the company’s former chief revenue officer, is running Sociomantic Labs, a Berlin-based ad tech company that’s expanding from its European base into the U.S.

Jumping from AdMeld to the start-up means that Kelly has flipped his focus. AdMeld was a “supply-side platform,” which meant it worked on behalf of publishers trying to negotiate prices with ad buyers; Sociomantic is a “demand-side platform” used by ad buyers.

There are a whole lot of demand-side platforms in the U.S. already — including Invite Media, the one Google bought two years ago — but Kelly says Sociomantic will carve out a niche by focusing almost entirely on e-commerce companies like eBay that “retarget” Web users who visit their sites.

One other big difference between Sociomantic and other DSPs: It hasn’t taken on any venture funding. Many of its U.S. peers are stuffed with VC money, at valuations that may prove difficult to achieve.