CPC_Andrew - 4:29 pm on Mar 17, 2011 (gmt 0)
Nothing with any of my clients. One thing to note is that your competitors, like Amazon, could be adjusting their keywords at any time, causing them to be more relevant than some of your listings.
Coupled with the fact that Amazon is Amazon, one of the most trusted shopping portals on the net, Google consistently ranks them higher than most online retailers.
Google does try to be fair in it's algorithm though, so it may have re-adjusted based on the sway in traffic that you and possibly other competitors in your space experienced.
There are so many variables that can impact traffic from this program.