recently I've noticed a lot of google results in the top ten are just newsgroup or blog pages with thousands of keywords. Only you never get to see that page because it redirects to another page that sells you the stuff. I could see how you can do this with 301/2 if you own the site but these initial pages are in public newsgroups/blogs which are - presumably - not under the control of the spammers. Question is - how do they do it?

I hope my explanation makes sense becasue I'm loathe to post an example!!