Link Bombing is much more effective when you bomb the target site from multiple domains (on different IP addresses). This isn’t always easy - you either have to convince a bunch of friends or acquaintances to join your cause or you need to find ways to place your links across different sites.

In order to do this free article directories have become very popular. Simply write some content for these directories and leave your link (with strategic anchor text) in your author bio.

This provides a benefit for you (some link love and traffic from the post), a benefit for the article directory owner (free content) and a benefit to the reader (informative content).