You might say ALOT of experience.
That said, it has it's good and bad points. I've given away alot of stuff without many problems, and I've offered alot of stuff only to get no replies and ended up hauling it into Goodwill or had better luck setting it out curbside with a "FREE" sign at my mom's. Be prepared for the occasional no-show, and I've had a few ask if I would deliver.
You can really get swamped email wise if you're offering something high in demand, I usually go by the first to respond and file a couple more for backup in case person A decides they don't want to travel the distance or they turn out to be a no-show.
The "wanted" ads can get really crazy at times, especially around Christmas. Any mention of money is a big no-no since they are a registered non-profit now, something to be aware of if you post ISO something. You can set the emails to daily digest if they start taking over your inbox, at times they can.