This is the mother of all lotteries: El Gordo (or the "Fat One") Christmas lottery in Spain. How big is El Gordo? Try €2.3 billion in prizes (about 3 billion dollars). And even better:
the this particular lottery's winnings aren't taxed by the Spanish government.
Hola Valencia blog has more:
El Gordo, the “big one”, is the most important prize in the Spanish Christmas Lottery — the largest lottery in the world. This year, there’s €2.3 billion in prizes (about 3 billion dollars). There’s a word for that: CRAZY.
Also: EXCITING. Roughly 18% of participants stand a chance at winning something, which ain’t bad odds. There are a limited amount of tickets; in 2006 there were 85,000 numbers. At €200, tickets are expensive, so they’re also sold in décimos at €20 apiece. If you hold a décimo of a winning number, you get 10%. [...]
I’ve read that 98% of Spaniards have some sort of stake in El Gordo, and the average amount invested is over €70. This helps explain the hugeness of the pot.
Link - Thanks Juergen!