AWA, usually I don't do much posting here (busy keeping up to date with changes), but I have to say, Google Adwords has had an "all of a sudden" drop in ROI in March on my side too. We're talking normally about $500 spent a day, and roughly 400% ROI, and all of a sudden it fell apart. It was so bad the other day that I actually lost money, that was the first time in about a year that I lost money in Google Adwords. I also noticed a spike in competitor terms as well for just one day. I would say that it's just a shift of some kind, but I can speak for others when I say that this is "all of a sudden".