It's dependent upon the search query. For a lot of long tail terms, Google pulls the top 3 listings from Google Product Search and places them above the natural search results. So you especially want to get in the top 3 in Google Base/Product Search/Froogle for these types of searches.
Hi there! Yes, the results you're looking at are for google base. This is a free service. Just sign up for a google account (if you don't already have one) and follow the directions under google base. You can upload a file with product info that lasts for one month, or create a feed.