One issue that plagues many paid inclusion directories is that search engines don't like them. Many times this is due to poor content, for example categories with no listings look an awful lot like spam pages since they have no content.
So I just spent about an hour cleaning up my paid inclusion web directory which is still well liked by the search engines (Google has 12,000 pages indexed and Yahoo shows 2,630 backlinks). I didn't have many empty categories since I started the directory with 300 categories and have added them as needed (and now have around 600).
All in all I'm confident that I'm doing everything I can to keep search engines interested in my paid inclusion directory while not flooding it with sites (which would dilute the value of each listing).
Posted by James Trotta at December 20, 2005 6:04 PMTrade links with seo-search-engine-ranking.com
http://www.seo-search-engine-ranking.com/ad_network_222.php