Yes, but it is frowned upon by the gaming community. As long as we are talking about MMO's. Steam or Xbox Live accounts you might be able to sell (I don't know about those) but that would be a bad idea as they are linked to credit cards generally.
As for selling it, eBay might not be your best bet for selling it. With a simple Google search I found a website which sells accounts on a large scale and will buy yours from you (see the related links). Look into more sites like that for a better sale is my suggestion.
sell them on eBay is the lodigal answer
go on eBay
eBay or auction house
no you will not find maybe some one sell it on ebay
You should sell baseball cards or Yugioh cards on Ebay.
Some of the rarest Pokemon trading cards are: Pokemon Full Art EX Cards - Some sell for nearly $40 Pokemon Gold Star Cards - Some sell for nearly $100 Pokémon Shining Cards - Some sell for nearly $150 Southern Islands Card Set - Some sell for nearly $300 Charizard First Edition - Some sell for nearly $700 Snap Cards - Some sell for nearly $700 Tropical Mega Battle 2001 - Some sell for nearly $10,000 Pre-Release Raichu - Some sell for nearly $10,000 Numbers 1, 2, 3 Trainer Cards Pikachu Illustrator Cards - Some sell for nearly $10,000
do sams sell pokemon cards
$20-50$ Sell it on ebay you will get someone that's really into poke'mon
eBay is a good place to sell cards.
I would suggest Ebay, that's where you're most likely to find someone who wants Yu-Gi-Oh cards. There's always Amazon or you can always ask arround/advertise if anyone wants to buy them off you.
If you have a hobby shop in your area you can sell single cards there or entire decks if you want to. If you don't have a card shop around sell them on Ebay or Amazon.
you cant sell any yu-gi-oh cards for a full price unless it is in PERFECT condition. but if it is a rare card you are going to sell you can sell it on eBay for a good price.