It is being reported that the man who held the toughest job at Google, Shashi Seth, head of monetization for YouTube has left the company for greener pastures - after only a year on the job.

“I think part of being a Googler is that you like smaller environments, and I think Google got a little big for me,” says Seth.

This is yet another indication that monetizing video is a lot harder than many thought it would be despite YouTube’s huge viral popularity and lead in the online video sharing market. Irrespective of the fact that YouTube made $80 million in ‘07 and is estimated to make $125 million this year, the Viacom lawsuit is a stumbling block. Even if Google manages to keep copyright violation payoffs to the $400 million allocated for that purpose in their $1.65 billion purchase of YouTube, they have a long video row to hoe in terms of pulling more than a revenue pittance per video view. YouTube is experimenting with video ads with text overlay ads, expanded text ads, placement targetting image ads, and click-to-play video ads.

There has been a steady stream of exoduses from Google in the last year. In March Sheryl Sandberg, Google’s Vice President of Global Online Sales left to become the chief operating officer at Facebook. In November, Gokul Rajaram, aka Google Adsense God, who was involved with the launch of Google Adsense quit. “When we started AdSense, it was just me and four engineers. The night before we launched, Sergey spent five hours with me testing the system and pointing out bugs” said Gokul. Not too long ago, Bret Taylor, who was one of the key people behind Google Maps left to start Friendfeed.