I think this is a dangerous tool, and should be encouraged strongly! Yes, you have to go on to Amazon to find out if a Kindle edition is available, but the style of cover frequently describe the book inside. I just sent some 10 book samples to my Kindle on account of this test run of Zoomii. If they prove as interesting as the available info (cover, blurb, reviews), then Amazon will have quite a few book sales from me.
The ones that didn't have a Kindle edition, went to my wishlist. Eventually I'll check again to see if they have a Kindle edition by then.