Sure, but that particular phrase won't help much (I tried), and I think it would be hard work to find a reliable set of words to filter away. Furthermore, you might remove more than what you want (for example the site you want, if it contains a link to sites for price comparisons).

The real problem is that you sometimes want to exclude classes of sites.

That is a great idea! In my simple test, it did filter away some of the annoyances (kelkoo for example), but left some other sites in (swedish sites, that's where I am). At any rate, it is a step forward. Thanks.

That is useful if a single site is the problem, but how do I say "I do not want results from any price comparison site"? This is a problem I see more and more of: searching for a product can bring up pages of more or less lame price comparison sites before meaning ful sites. The actual producer of the product you are looking for is surprisingly often way down in my listings.