The main method of getting sites to link to you is called "reciprocal linking," or in normal words, link exchange, since this way both sites improve their link popularity. This process can be time consuming, and needs attention even after the deal is made. Here’re some examples of possible pitfalls:
1. A site might link back to you, but then get rid of the link, or move it to a different part on their site, that isn’t ranked as highly.
2. A webmaster might place a “rel=nofollow” attribute in his ling to you, which makes a spider ignore the link when crawling the page.
3. Your link might be placed on a link page that exists on the site’s server, but doesn’t have a link from the actual site to it. That way a spider is highly unlikely to reach it. And if it does, due to manual submitting for example, it will not give it a high rank, no matter how popular the main page is.
4. Some webmasters will point the link to a script on their page that will redirect to your site. Since spiders don’t read scripts, this link is useless SEO-wise.
5. When purchasing links, some sites will place the link on every page of their site. Google has recently begun ignoring such schemes.
So unless you remain watchful and monitor your links constantly, you risk increasing the other sites’ ranking, but not your own.
