Peter Kafka

Recent Posts by Peter Kafka

One More Googler Gone: DoubleClick Ad Exchange Boss Michael Rubenstein

google-logoGoogle employs about 20,000 people, and I don’t expect to write a story every time one leaves. That said, here’s another one: Michael Rubenstein, who ran DoubleClick’s Ad Exchange unit and who was running the same project after Google bought his old employer last year, has left “to pursue another opportunity.”

I’ve been trying, unsuccessfully, to find out what Rubenstein is doing next*. Google hasn’t filled his slot, but is looking externally for a candidate, I’m told. His former boss, DoubleClick CEO David Rosenblatt, left in May.

UPDATE: Rubenstein is now president of AppNexus, which describes itself as a “a cloud computing and real-time online advertising platform company”. I asked him to explain what that meant today, and he was intentionally vague — but noted that cofounders Brian O’Kelley and Mike Nolet are both veterans of Right Media, the ad exchange that Yahoo (YHOO) bought in 2007. So “there’s a lot of exchange knowledge here,” he deadpanned.

Rubenstein’s departure is worth noting because the unit he has been overseeing is small now but could be important for the ad giant’s future. Google (GOOG) hasn’t formally unveiled its Ad Exchange, which is supposed to bring together ad buyers and sellers in the same way a stock exchange does, but industry folks are already using it on an invitation-only basis. (Google’s “real time” ad bidding system, which is separate but parallel to the Ad Exchange, is also an open nonsecret in the ad tech world).

*Are you Michael Rubenstein, or are you someone who knows what Michael Rubenstein is doing next? Great. Please drop me a line at, or use the blind tip box here.

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