As a 2,000 point certificate is worth 40 Euros or 60 dollars, there is now some real arbitrage available, PROVIDED the exchange rate used by the hotel is fair. At the current Euro/Dollar exchange rate, $60 translates to about 50 Euros. So the question is, how does the hotel compute the exchange rate, anyone know?

If it is using the rate that the guest would get if changing money at the desk, it's still possible to get ripped off.