Open Site Explorer is a free online tool that can help you figure out which important domains are linked to your site and sites that are using the rel=nofollow tag while linking to you. You may use this data for:
- Researching the links that point to your site to identify content that discusses you or your organization
- Discovering errors or omissions in the links that point to your site(s) for correction/improvement
- Investigating the link data of a competitor to determine where they’re earning press/attention so you can reverse engineer their marketing efforts
- Comparing link metrics between multiple sites to determine the level of competition / difficulty /importance of your own site in comparison