I personally think biggest problem are the people who are buying gold, making this spamming even possible. If people dont buy gold there is no spammers. I hope Zenimax will come hard with their ban hammer on those who buy gold.!
Other than that i think most accounts that are selling are some kind of hack or exploit and are not real accounts. But thats just what i think.
Eventually the account does get banned but often it takes awhile to do so.
Then they tend to steal the accounts of people that use their sites basically if people didn't go to the sites they wouldn't be in game so if they are in game someone is going.
I've always pointed out(and wrote a paper on for a econ class lol) that games like Eve Online that have a in game item you can buy that if used gives game time and can be traded to other players then gold selling stops and the company(Zenimax) makes all the money.
What happens is people without a lot of time to play but money to burn(the ones often that go to the spammers sites) get's the item and sells it to a more hardcore player for gold and the hardcore player plays for free.
However he's not really playing for free the other guy just bought his game time for him basically in exchange for not having to grind it himself this is how the economy works all the time, You don't want to level say Blacksmithing to make epic gear so you buy it, Time for Gold.
In other words A. It does not hurt the game economy, B. The Company(Zenimax) makes the same amount of money C. it's no different from any other exchange that happens, D. No gold spam because there is no market for it you can get gold in a legit way.
I see more games doing this these days but if you don't you'll have spammers end of story.
EQ2 has this in place. The in game item is called a Krono. Players can buy them from SOE. The cost in real money is slightly more than the cost of the monthly subscription but they are fully tradable in world and can be sold/bought for gold (or in this case Plat). It works like this:-
Player A purchases the Krono from SoE and pays cash.
Player A puts the Krono on the In game marketplace and sells it for Plat/Gold.
Player B Buys the Krono for Plat/Gold.
Player B pays for his next months subscription using the Krono.
In effect Player A is Paying SoE for Player B's subscription.
Not sure why people ever want to buy in game money anyway. I have never needed any more gold than I can generate in game. I guess it has something to do with the 'Gimme'/'Must have' society that we live in now. It's preety much the same mentality as people buying a Mount or vanity/fluff pet for cash. I see people riding around on the store bought horse and I think that idiot paid £10 for that.