I would stay away from it. My concept of how I use my cards are that A) I develop an energetic relationship with my cards. and B) then channel the energy of the person I am reading. I hardly think that a computer could do that, it would have to feel and it dose'nt.
It is a good way for a beginner to learn the meanings of cards. Other than that I'm not sure that it works all that well. And you still have to make sure the author of the site knew the right definitions.
I think it is a fun game, and sometimes they seem right. It is a random selection, but I agree with mysticalowl, it is a good way to learn the card meanings, and it is also a godd way to preview decks.