How about using KeywordSpy? - This will give you an opportunity to immediately track down your competitors and gather keywords for the promotional campaign of your online business. It offers Free trials.

KeywordSpy is keyword research technology where you can also earn and even surpass what your competitors are making with Google Adwords and Overture. KeywordSpy gives you the key to their success: a good ad-campaign with the right keywords.

It also has a ClickBank Affiliates Search Engine where you can see the actual market landscape at ClickBank.