Ours did significantly. It went down from a consistent 74% to 11% in Google Analytics. I'm trying to figure out why. Did Google's algorithms change then? I don't think it's anything I did. I upgraded to Xenforo 1.4.4 on the 16th Jan. And added Trending Topics on the 25th. Neither could have such a significant change, I'm sure. There was a big sitemap update on 19th. Could that have some influence?