Expired Domain Names Potential Problems

Existing domain names are expired everyday.  If they already have a back link structure to them you can purchase the domain and put up content on the site related to the incoming links. In this new content put some AdSense or affiliate links to related products and services. The traffic it is already getting through its link network can provide additional income thus benefiting from the work of the previous owner.

Problems arise when a site has used unscrupulous SEO Tactics in its web promotion. You are buying those problems and penalties applied to that domain. Also if it has a good Google Page Rank it will not carry over since Google wipes the slate clean upon expiration.

 Now, this doesn't mean that purchasing an expired domain isn't a good idea. You'll oftentimes get a desirable domain name with good incoming links which can generate traffic but don't count on page rank being a relevant factor.