Goggle (which at one time was one of the last search engines to not display search results on the basis of receiving compensation) has now fallen (old news, but this is a discussion topic in one of my classes this week). I think Google currently does a good job of shunting the paid links off to the side, but I'm still concerned about the implications of this for educational uses. Kids have a horrible problem with information literacy, and I'm not convinced that it will be immediately obvious to some of them that these are paid. Even if they make the connection they may not see the implications (since their levels of trust for websites on a scale of 1-10 are what I would call "scary high").
One of the biggest offenders in my mind is Yahoo. Yahoo (because it also has a heirarchical search mode) adds searchable content through the use of human editors. As you can imagine, they can't really keep up with the number of web sites being created. Since some people have extra cash, Yahoo will let you pony up 299.00 a year if you want to expedite this process (a 7 day turnaround guaranteed! woo-hoo). The sites that pay the extra "3 Benjamins" are not (as far as I know) flagged in any way as having paid this money.
I think this is bad in the context of education. Espcially when you consider who has extra money laying around (not to mention who doesn't). And let's stop and think about this for a second. You need to pay an annual fee or else your coverage gets dropped? Do they send Nunzio over to make the collection?