Link Diversity definition: having different types of links pointing to your site.

This means that you will post some blog comments, build forum profiles, guest blog posts, etc.  Basically having as much variety in your link building strategy as possible.  This helps hide your links from competitors.  When you’re trying to get a number 1 ranking, the easiest thing to do is steal your competitors links.  That means you go to each site where they have a link, and try to get a link.  This is one strategy that is very common among professional link builders.  The exact strategies are different, but the principal is heavily used.

The only way to stop link builders from stealing your links, is to bury them in junk links. This is the first reason why you want link diversity.  The second reason you want link diversity is to protect your site from future updates.  Every update Google implements adjusts settings that you see in the SERPs (Search Engine Ranking Pages).  If you have a single type of link and that type of link gets devalued, you’re site is going to drop in the rankings.  If you have a variety of links, you have a better chance of keeping your ranking.

Need proof?

During the last Panda update, a lot of sites lost rankings.  Not a single one of my sites dropped in rankings.  Just because I love Market Samurai, here is a picture taken today showing my rankings.