Anyone now can promote their musical work and make it spread and reach a great number of audience, which they may turn out to be fans, and obviously this is the way how bands can get bigger, when fans exchange music, promote their fav bands whether by playing their covers, forums or anyhow... but, i was wondering how it works the other way around, how can bands know that they have a huge fan base in a certain part of the world? what if for example in Tunisia,we have a pretty good fan base of Dream Theater and Symphony X and of course Metallica, do these bands know about it? How can fan bases be promoted to bands? is there any way?