The success of browser mmorpgs or How to get free spammers

Have you been spammed by people with links pointing you to some online game you must register for and telling you how by clicking the link you just gave the spammer an advantage ? Well if you haven't then you're really lucky.
These types of sites have become increasingly popular. Most of them promise some sort of prize at the end of the game. But the most important aspect is that in order to advance you have to get your "friends" to go to the link pointing to your account. This maybe gains you some points and in turn guarantees the site gets free advertising. The result being of course massive spam.
The strategy isn't at all new. Web sites have been using this form of advertising for some time now. If the link ends with =[user_nick] then it's pretty clear. They just take advantage of the thousands of ignorant suckers out there willing to spam. And why not? When it's so easy!
The way to put a stop to this is simple. Just don't join! If it is clear that the site uses this type of advertising just don't sign up. I won't say that all of them are a scam but most of them are. They might say they give out things to the best player of every month but there's no way to verify this. Meanwhile they are getting a lot of money from advertisement.
And the way people like that work, is they set up a new site, spread it around, and when the users stop spamming the link so much they just close it down and start a new one in the same format. A copy, just with different themes. No matter what they promise you, it isn't worth it. Just stop spreading the link, and tell your friends the same. If the link isn't spammed so much, they are forced to close down the site because the advertisers aren't paying.
That sort of spam has to stop and people should be informed they are just being used for profit. If they get they are waisting their time, working for someone else for nothing at all, they will stop.