I just read BlueHat SEO on Link Laundering (google it.. I can't post links yet) Does anyone have any experience building these types of directory websites? I have had a few ideas on promoting a few "blog contests" and requiring each contestant to write a 100 word blog post to "win" with a link back to the blog contest site and a sponsor (sponsor is main site). Similarly, I could do the same thing and convince users to link back.. then 301 redirect (does that still work?) Would these work?