Oh yeah, they are constantly hoovering up huge collections so yeah, visual assessment almost exclusively, or an occasional spot check. They used to cater more to beat diggers (who just wanted a clean-sounding break) and jazz heads. It also used to be harder to find stuff, at least with the online marketplace, so you weren't sure if you were going to see some private pressed Chicago jazz side again in the near future. Now, the market is wide open and even with rare titles, one usually encounters one or two a year.