Virtual currencies! Not like Bitcoin, I mean in computer games. Tribes Ascend has gold. Planetside 2 has Station Cash (more commonly referred to as Smedbucks). You exchange real money for in-game currencies and then you exchange your in-game currency for an in-game item.
It is a terrible idea. It is confusing. It's a second layer of confusion. I assume it's to prevent people from feeling like they're spending real money on virtual items, which is fair enough since it is a remarkably stupid idea, but it might worth on trivial amounts of cash. But when I'm wondering if maybe a second burster for my MAX might be worth buying, I am presented with a cost in an arbitrary number in the unit of 'smedbucks', some stupid unit of currency that only exists on a select part of the internet.
Lesson #1 in selling things, SOE: don't make it hard to buy things.