The following tools can be used to obtain a list of locations on the Internet that are linked to your competitors’ Web sites:
Enter your competitor’s URL in the search box like this: link:
yourcompetitorsURL.com. The results will contain all Web sites linking to
your competitor’s Web site.
Link Popularity (http://www.linkpopularity.com)
Simply type in your competitor’s URL and it will give you a list of all the
sites linking to that particular site.
In the SEO tools area there is a link popularity tool. You can put in three
Web addresses and get a report on links to each of the addresses.
IconInteractive has a link popularity tool which gives you information on
links and also an Alexa rating.