A WebmasterWorld thread reports that Google is now placing product results, for some searches, in the middle of the search results. For example, a search on ipod nano returns the Google Shopping results in the fourth listing, as opposed to above the web search results.
Yes, this is Google Universal Search at it's best, but it is confusing some users. A WebmasterWorld member asked why Google was placing AdWords listings within the search results. Yes, you and I know they are not AdWords listings, but does the average searcher? In that case, does the average searcher care if there are product results in the 4th listing, mixed into the search results? Maybe not, maybe that is what Google is testing.
For you, the advertiser, if you have product and you are not in Google Shopping/Product Search, then maybe it is time you submit your products to Google.
Forum discussion at WebmasterWorld.