SEJ -- Jan 11 -- Choose relevant on topic websites. Don't buy just one link. Buy links for at least 6 months. Do a check up half of the way through and make sure things are moving in the right direction. Don't buy for soley link popularity, instead buy for traffic. Anything below 10k Alexa will have real traffic. If you aren't getting any direct ROI from that traffic, re-evaluate what and why you are buying those advertisements.
Air on the cautious side as Google tends to penalize sites for buying some links, or buying too many, so they need to meet the right criteria of acceptable advertising, which is traffic, relativity and placement on the page. Spend the money on a good release and distribution. FULL ARTICLE @SEJ