7 . Give an unbiased testimonial on a product/service that you have used in exchange for a backlink to your site.

How it works: Highly popular or established product pages will have Page Rank. By posting your domain on their site they pass some of this PR to you.

Pro: Free.

Con: To get full SEO benefits, the product/service must be somewhat related to the niche/category of the site you are building links for. Finding relevant high page rank product/service sites can be time consuming. You are filtering for a) category b) Page Rank and c) do follow. Thankfully, there’s some tools that can make this task easier.