Last month, Apple began tweaking its App Store to more accurately rank applications based on criteria besides the number of downloads. Presumably, this new rating system takes into account both app reviews and ratings from customers. To tighten up the reviews and keep them honest, Apple has reportedly implemented a new policy that prohibits people from leaving a review when they obtained the application using a developer promo code.
A forum post at Touch Arcade contains an email purportedly from Apple customer support that describes these changes. The support personnel writes, "I am sorry to inform that it is no longer possible to rate or review an app if it was downloaded using a developer's promotional code." Anecdotal evidence suggests this policy applies to applications recently downloaded with promotional codes. Promotional applications downloaded from a year ago still allow user reviews. Though inconvenient for some, these changes are consistent with Apple's desire to shore up its App Store ratings system.