The debate on whether Google is telling the truth about click data, i.e. pogosticking, clicking on a search result and jumping back to the search results page shortly after, influences the rankings of that search result is a topic that won't die.
In short, Google says they do not use click data for ranking. They said it is a hard metric to use and it is easy to spam. Moz says they ran tests, several of them over the past two years, proving Google does use a form of click data for ranking.
So the two, Google's Andrey Lipattsev & Moz's Rand Fishkin, were in a Google Q&A via WebPromo hangout yesterday and discussed it around 14 minutes into the hangout. It is really interesting to watch. In short, Andrey Lipattsev said it's a tough challenge to make click data a strong signal and it is 'gameable' metric. He added that pogosticking isn’t always a good metric because sometimes the user behavior for the query might warrant them clicking, reading and going back to the search result quickly.
Andrey also added that Google statistical tests have shown pogo sticking in the search results don’t make for better quality. Rand said in their own tests, they've shown Google does use it.
So why did Rand's tests shown ranking changes with mass pogosticking? Andrey said without looking at the specific data, that is his guess would be that the burst of searches, social mentions, links, etc may throw Google off a bit and then they figure it out over time. But he said he needs to see it in real time, which Rand agreed to run another test, with Andrey watching in real time.
I recommend you watch it, here it is embedded (again, jump to about 14 minutes):
Forum discussion at Google+ & Cre8asite Forums.