I will answer this in two simple ways. Obviously you are on Facebook if you are wondering this. Click on some friends page and photo albums and look at the ads. Do any of the ads you see on the left hand side strike your interest? The ads next to this writing are what I see all the time when I am online reading about what my friends ate for lunch and reading about ex-girlfriends changing diapers in my newsfeed.
Here is my breakdown of how the ads apply to me; While I am a Fugazi fan I would never go to a event on the punk-folk connection in 2009, I may have gone to anything featuring Fugazi in 1996, but now they are simply something in my interests because it is part of my history. There is no way for Facebook to know I have them listed in the music I like as more of a “part of my past thing.” As for the second ad – I love Brian Eno, but there is no way I am buying a shirt of him and wearing it in public, until Facebook gets a algorithim to see if I wear shirts of weird looking rockers this isn’t very effective. Lastly, I have absolutely no interest in work out methods so the third ad seems totally off base to me, meaning whoever paid for this ad to be before my eyes failed badly since I would never click on any ad about my abs.
To me that means Facebook isn’t targeting my interests very well. This doesn’t give me confidence that if I took out an ad on Facebook that they would do a good job of targeting people. Though when you go and look at the ads you may have different results from me and if you feel like they are targeting you, maybe it is worth it?
The other question I would ask you before placing an ad on Facebook would be have you done everything else you can to promote your band that may be more effective? Getting your music on online radio like Pandora, Jango, and Last.FM is a much more effective since people get to hear your music that are interested in your style. Would your money be better spent going out and socializing, meeting people who may like your band, getting a better PA so your band sounds better? Probably! But if you have a large budget and have already done many of the other means of promotion Facebook ads may be up your alley.