"Now, it is possible that some extremely niche businesses have found limited utility from ads (for example, BustedTees and social games may be the lucky few)."

"Now, it is possible that some extremely niche businesses have found limited utility from ads (for example, BustedTees and social games may be the lucky few)." Um, I don't know that I'd refer to to social games as an "extremely niche business". Also, social commerce/group buying sites have received incredible ROI from advertising on Facebook.