Is It Really a Contest If You Have To Buy The Book First?

I recently had a contest where readers could win several copies of my latest release, and all they had to do was either show up or put their names in a hat, per se.

The reason I mention this is because on one blog I happened to peruse the other day, an author is giving away two gift certificates to a bookstore as a prize.  But in order to have a chance at winning one, you have to either write review about her book on her blog, or write the review for her book on Amazon.

In other words, you have to buy the book first, read it, and give her a favorable review before you can be entered to win.  (I seriously doubt a bad review would make you eligible.)

To me, that's a contest that's going about it all wrong.  Or am I missing a very crutial point?