There's certainly not a lot of money in MP3 sales.
Ok, there is, what with iTunes now being the #1 music retailer...
But I digress. I like that people are giving out digital copies of their music. I don't want to pay for MP3s. I don't mind buying CDs; that is a physical object that has a cost to produce. But I don't like having to pay for an entirely digital (and reduced quality) product.
In counterpoint to DavidK, a good portion of live music nowadays is simply playing back the recordings. Bands go to great lengths to make their live shows sound exactly like the album. Worst-case, they just reverse the process. (i.e. the album sounds exactly like the pre-recorded live show).