Over the weekend of 6/25/2011, Google appears to have made a change to the requirements for their Product Search feed. If they announced it, they were very quiet about it.

The change is very simple - ID is now a required attribute instead of a recommended one. The ID is described as an 'internal identifier only', so we're going to use productID for that field. There's a very simple mod documented at http://manual.aspdotnetstorefront.co...ch-update.aspx that will enable that on your site.

Note that this is separate from the changes made earlier this month regarding shipping & taxes.