Because they're stupid or tragically misguided in their priorities. Don't fall for such things, it's just a game, for Christ's sake. Buy some food, or something.
You have to spend some of the virtual money in the store and buy it.
I'd suggest Free Realms or Wizard 101.
According to Time Magazine people spend money because they feel lonely.
there are a few programs determined, and made to help you keep track of the money you spend, but as well there are credit card websites, (cough* discover card) that allow you to track the money you spend on your card. Most banks have websites, and you may be able to check your balance on those.
B/c they have a lot of money to spend.
to spend it
Beer
They spend on basics things they need most like food and detergent
People in London can spend money on different things so next time be more specific on what your asking
Entropia Universe was created by the software company MindArk. It is a huge multiplayer online virtual universe. Players buy in-game currency with real money to spend on virtual items. Those items can then be sold for real money.
vodka
World of Warcraft is extremely educational you learn how to save and spend money on potions and armor