We make use of the Steam-API, so it is not necessary to build a new account for this website, the only thing you have to do is login with your own Steam account. Safe and easy.
You earn coins by completing offers and surveys. Many of them are completely for free, so you don't need to invest your real money. You can also get coins for your daily login to this website and for inviting your friends.
When you finally got enough coins, it is possible to exchange them into CS GO Skins. After you buy a Skin you receive a message with a Trade request on Steam.