I sold a domain on afternic a week ago. Sell about one every 3 weeks with a portfolio of 500 domains. Right now I’m listing everything on afternic and undeveloped. I’m switching to 100% afternic reading about payout issues with undeveloped here on Namepros.
So far in 2019 I've been making one or two 4-figure sales per month.
I honestly don't know how I've done it .. those who follow my daily auction/closeout lists know that I've had an insane amount of crap (non-domain related) going on in my life sucking up a ton of my time .. as such a large portion of my domain aren't priced or even listed at most market places (none of my domains are listed at Undeveloped or Uni).
My sale are all over the place .. mainly incoming via WhoIs, then also a bit Afternic and Sedo.