@MG - While that's is a great theory and generally a good practice to understand your buyers, our data says it's not a change in the buyer, but rather a change in the volume and quality of the buyers.
Mayday was the last update to really pound us into the ground. One day we are clicking along just fine, the next day nothing. That's not buyers suddenly becoming more savvy.
Same case this year, we are clicking along fine from the first of the year right up until Venice is released upon us, then Bam! suddenly sales drop like a rock.
I do agree that buyers are becoming more savvy, but that is evident over a longer time span. In 2008 when the economy was bad, I was doing double the sales on half the traffic. Now I'm at double the traffic of 2008 and half the sales. Buyer savvy accounts for SOME of that, but not all.
The scope of Google's product has become too large and distracting. Now rather than using the search engine to find things, it now leads users away from sites and onto videos and social networking, which by my definition is one of the biggest time wasting networks every devised. However I digress.
You're right though, it's an art form. But right now that art looks like it was made by Koko the Gorilla!
BTW - I also tried to blame it on the recent warm weather, but that doesn't hold either. I ran our past numbers against weather records and warm / cold spells had only a minor effect on sales.
[edited by: backdraft7 at 1:25 pm (utc) on Apr 2, 2012]