For buying music online, it's hard to beat the instant gratification of a download. But if you perform live, chances are you'll sell more product at the gig than you do at CD Baby.
Buying CDs at the show is still popular, even with younger crowds. It's a physical memento to take home from the show. You can get it autographed. You can read the credits. You can listen to it in the car on the way home.
But get some cheap USB flash drives, copy your album to it, and offer it for sale as an alternative to a CD. Some fans will buy both. And don't forget the T-shirts!