Putting aside the fact that Silicon Valley is doing a lot more than whatever makes the front page of TechCrunch today, there's still the fact that in order to get an ad impression you have to provide something that an actual person somewhere ostensibly finds useful. At it's worst this is orders of magnitude more useful than Wall Street's endless arbitrage seeking to benefit the richest of the rich without actually providing anything that is useful to someone with less than 10M dollars.