It's an online currency, similar to paypal. Except, instead of sending dollars or euros or whatever, you send certain amounts of gold, or silver or palladium. This way, what you have in your account is independent of currency value changes.
I think rewarding members is a great idea, and I'm sure it will attract a lot of new members. I don't know any ad networks that pay by egold though... Why not just use paypal? Most networks use paypal.
