I'm of mixed feelings about such things, on the one hand I have a bit of a hard on for Amazon, they're really doing their best in so many ways, good CS, building good rep, trying to keep customers happy as they branch out into new service areas.
On the other hand I agree that most of these services are essentially scamming lazy people with too much money. If you find yourself in need of such services you probably should ask yourself why you have so much stuff to sell.
That said it's not my place to tell you how to live your life, so I'm happy to give my thumbs up to Amazon services, they really do their best to keep people happy so you're unlikely to face a horror story like the previous posters.
How is it any different for electronics...? I got a 32gb 4th Gen iPod as a gift... I don't use it at all... Literally it has been laying on my keyboard tray dead for like 3 months... They will give me $143 for it... That's $143 more than I have right now for something that is entirely useless to me...
I don't see how I am being scammed - I've never used ebay... So I am not selling it there...