Any of the small $ I may get from a gig here and there gets funnelled back into my music hobby. Whether I go out and buy some records, or cds, or buy some piece of kit, or repair something broken from a previous live pa done.
I can compare buying music/going to shows with my history in skateboarding and snowboarding in that it is always fun to be off riding by yourself but when your are sessioning with others and feeling their energy and creativity, it pushes you to try different, or harder "tricks". When I buy records/cds/ go to shows and hear others playing/creating, it always jumpstarts my own juices to get moving too.
I love putting on a record in the shop either from an artist I know, or someone I've not heard, and standing there with a stupid grin going "aww shit, that is SICK!" Makes me grind my teeth with the groove and go up to the counter feeling happy to support that person/label.