Keyword Discovery

Keywords Discovery: http://www.keyworddiscovery.com/

Sounds like a great service:

Linking strategies, affiliate programs, site sponsorships and website
advertising can generate substantial traffic. The KeywordDiscovery referrer
reports tell you which sites drive the most traffic to your competitor's pages.

This service simply gives you an overview of what referrers drive the most traffic to your competitor's website (list of referrer with percentage of traffic they generate compared to the overall one).

where do they get the data from?! the service is very cheap, far cheaper than hitwise for instance. Cannot imagine that they have got agreements with ISPs. I have contacted them about that... waiting for an answer.