This plugin detects links to external sites mentioned in the big list and puts ‘nofollow’ tags on them. ‘Do unto others as you would have others do unto you.’ WordPress is a major blogging platform, with millions of users. If many people using WordPress use this plugin, other big sites may reconsider their ‘nofollow’ strategy. This plugin expands on Wikipedia nofollow plugin hacked by a revolted blogger.
This helps in your blogs search engine optimization
To add your own site to the list just add a new row by editing the plugin. This plugin helps in controlling the page rank flow and passing PR juice to relevant and useful pages only.