What I do not understand is the knee-jerk reaction to mp3s, the thought that any sort of mp3 proliferation is bad. The fact is, if it weren't for mp3s, many of us wouldn't have discovered bands like Stratovarius, Symphony X, and a host of others. I know of people who didn't realize that good metal was still alive until they found mp3s! Because of the mp3s out there, MANY, MANY people have purchased scads of CDs.
mp3s only harm sales when someone downloads, doesn't buy, and keeps listening to the music. That generally only is a problem for the Top 40 crap bands who have no real substance. Let's face it, anyone who hears something that moves them WILL start buying CDs, merchandise and will try to catch concerts.
I will d/l things to see if I want to purchase a CD. If it really appeals to me, I will purchase CDs, t-shirts (what few bands will have them in small, mind you...) and become a fan. If it doesn't...DELETE and move on. How is that different from hearing it on a radio? Because I have the file on my computer? If any radio stations in my area didn't suck, I could just as easily tape record a song. That doesn't mean bands are wanting to not be played on the radio, does it? A taped song off the radio is probably of better quality than an mp3, or similar. Of course, they don't play anything worth taping on the stations in these parts...
There is virtually no threat to bands who have substance, talent and respectability. Who the hell would want to listen to only mp3s of their favourite music? The quality is crap, you don't have the lyrics, no cool artwork, nothing to blast in the car or the home stereo (okay, you can with some devices, but it sounds like ass). No one who would consider themselves a fan of any sort of music would have only mp3s.
When it comes to underground music forms, getting the music out there to be found will only help to get it sold.
And, yes, I've been close with many unsigned/independant/small contract-type bands for many years so I know what it's taken to get the music out there and the band known.
If someone enjoys your music, respects your talents, they will buy regardless of the availability mp3s.