Upon completion of the rental period, the owner and the renter both receive a request to write a review about the booking and each other. This is very useful because it'll make your profile increasingly appealing towards other Gearbooker users. The reviews are displayed on your personal profile page. Both by these reviews and by the several verification steps in your profile (such as your ID, phone number, email, etc), you'll move from a status of Gear Newbie, via GearFan, GearExpert, GearGuru to even GearMaster!