In Piper Jaffray’s April 18th 2008 Industry Note on Google’s Conference Call, Aaron Kessler and crew point to the following negative remarks from Google:

On its conference call, Google indicated that it is seeing signs of slowing in U.S. eCommerce. “I think in general we saw in Q1 a bit of slowdown in retail, some postponement of budgets.” Google’s comments confirm our recent eCommerce survey, ComScore spending data, as well as SEM data which suggests slowing eCommerce growth in the U.S.

The note also mentioned a recent SearchIgnite study, but I’m waiting to review the whitepaper myself before adding fuel to the fire.