Former Feedburner CEO and Co-founder Dick Costolo joins the stream of senior level ad exec departures at Google within recent months. Google (NSDQ: GOOG) bought out Feedburner for $100 million in 2007, and quickly integrated its RSS feed monetization technology into AdSense. (It also aggravated many publishers with bugs and errors in the process). Post-acquisition, Costolo moved into the role of group product manager for social ads, TechCrunch reports, but now he’s resigning.

SEE ALSO: Google Shuts Feedburner Ad Net; Publishers Offered AdSense For Feeds Instead: Report

Costolo offered no details on where he’s headed, but his departure follows the exit of former DoubleClick CEO Dan Rosenblatt in April—not to mention a steady stream of resignations by high-level ad sales and management execs in the wake of ad chief Tim Armstrong’s defection to AOL.