I have a small PR3 directory based on phplinkdirectory script.  This morning I actually received an email from a listed site owner asking me to remove their site.  I wondered why someone would actually want me to remove a link. I used to think that any link on the internet pointing to your site can only help you; that no links could hurt.  I did some research and I am slowly finding out that this is far from being true.

Examples of bad links include
- Old bbish message board systems from the early 90s
- Overspammed guestbooks, message boards, and blog posts
- Links from sites that sell text links
- Some link directories

Of these three sources of bad links, I would have to say that links from sites that are obviously selling links are the worst to have.  Why?  Link spam rarely gets examined. If it’s overspammed, it’s quietly discounted. Sold links are different. They get examined if someone reports them(or the sites they’re connected to). So you risk an actual penalty off those if they decide to add your site to the hit list.

As for directories… A lot of directories ARE spammy link farms. Either low editorial guidelines, or run by Indian SEO firms who will submit to 100000000 directories for $10 or whatever. The firms generally OWN the directories, which results in them having exactly identical sites. And that makes them an easily spotted link farm.