How do Stumble Upon match paid ads to favorite stumble results to a member??? Is that the full business model of matching paid ads?
StumbleUpon = eBay In my opinion, stumble upon lost any hope of being a credible social networking site when it was bought by eBay.
I personally dont think it will, they won't interfere with the day to day running of it. Not yet at least.
It is a great tool , it would be hard to ruin it, but big businesses know a thing or two about ruining what is good. Soon as te start messing with results, SU could get annoying.
I dont fully understand your question, but I do purchase a lot of traffic from stumbleupon. http://www.stumbleupon.com/ads