Good point. There're just too much hassle for majority of people to particate in feeding input. But do give the website a check. There is indeed a good amount of information available. Although average person would not bother with it (perhaps just use it to check the price), there are enough enthusiasts who would go far enough to actully get online back home and feed useful information into the system.

The success of a system has much to do with building a community rather than the software system. The higher participation level it has the more useful the database would be. Which in turn raise the profile and attract even more participation. In gasbuddy there is a score system that motivates volunteers to feed data regularly.