Ever since the App Store started, one of the biggest complaints from numerous individuals was the fact that many people were leaving reviews for applications without even purchasing them. This led to inaccurate reviews left by people who actually had no right to be reviewing it without trying it. However, Apple has put a requirement now that users wanting to leave a review must now have first purchased the application.

I think this will definitely help get more accurate and mature reviews for applications, rather than the very immature and half-baked reviews that are on every application now.