Thanks for feedback. It's based primarily on Open Street Map. It's always up to date and I can make some corrections to data independently of data provider. This approach has some downsides of course and I'm thinking how to improve it. Open Street Map is quite reliable but someone may just stop accepting Bitcoin and forget to remove the place from OSM database. Maybe it will be removed by someone later but still place will be displayed on the map for some time.
Not sure about the solution yet. Adding "verify" button would help to improve data reliability. So people would be able to mark places they visited and it will add more confidence to other people. It's better to try cafe or ATM with 10 verifications than 0 =)