I am having good success with an ad I posted on a certain classified site. I was checking the inbound links at www.check-backlink.com and saw that it had around 700 backlinks all from subdomains of the main site. Check-backlink.com is seeing subdomains as inbound links and my guess is that google is too. This must be the case as every ad I post there rocks to the top of google. So my point is why not set up several subdomains on your main site and using some autoblogger or YACG post thousands of pages on these subdomains all pointing to your links? I think this is old news but I dont see it used much. Why spend so much time link spamming when you can create a monster on your own domain?