For example, your age, gender and location.
Why should we include this information: We want to make sure that you're a real person who will be able to use the product after purchase. This isn't some sneaky way for us to harvest your email address - it's because we genuinely want our customers to enjoy their purchases!
Provide a coupon code with expiration date in the text of your review. If possible, include a URL where you can find more information about the coupon code (like on Amazon or elsewhere).