Back in the early 2000's I used it quite a bit, both buying and selling.

I think my last transaction (purchase) was in 2018. I don't think I've sold through GB since 2007 or maybe even earlier than that.

Gotta watch out for those that automatically add charges for CC use.

Biggest issue I have with GB selling is that apparently you now need to have an FFL at both ends? I know the last time I sold a handgun (maybe 2006? Not sure) only the RECIPIENT needed to be an FFL. But I think with handguns (and maybe long guns, not sure) all sales need to go from FFL to FFL which means paying someone to do the transaction at both ends.