An authoritative link to your site counts as one vote toward your link popularity. Non-authoritative links, including most reciprocal links, three-way links, and, certainly, purchased links, count as nothing. Generally speaking, a lot of nothing adds up to nothing. But problems can arise if the majority of links to a site originate from sites that Google has penalized or banned.

To figure out if Google has banned a site, use the Google Banned Tool. Or, try the site:www.thedomain.com command in Google to see how many site pages are indexed. If the top-level domain isn't indexed by Google, it either is a brand-new site or has been banned. Since a banned link generates zero traffic to your site, it's logical to request the link be removed.

A simple e-mail to the site's Webmaster requesting the link be removed gets the task accomplished 70 percent of the time. In one instance, a Webmaster asked if we wanted to be removed from all of his "automatically generated" content sites (think link farms and contextual content scrapers). As a result, that single e-mail request got 30 links pulled from 10 banned sites.

Get the full story at ClickZ