They do a swap meet a couple of times a year, I believe.
I missed the last one.
I won't miss the next.
(Famous last words!)
But yeah, Joe sells donated, unwanted (historically speaking) bikes out front (he also posts them on Craigslist pretty often), and they get donations all of the time, which they often sell bits from in order to keep the lights on over there.
It's an excellent establishment run by total legends and friendly volunteers.
What's not to love?