Oh great, hopefully that will help you get reviews. It's definitely taken a few weeks for me. I think I had one review after one week, but since then they have dribbled through slowly. It's been up for nearly a month now. It seems to me that the review rate is about 10%, i.e. if you get 10 people requesting the book, then you are likely to get one review. It could vary a lot between genres though. I've only done it once, so not a lot to go on yet!