This is such a great idea! I've had a subscription for a few months now and recently used the service to book a flight to San Antonio, TX. I didn't quite have enough points and used the "instant buy" option to get the needed points and was able to book just fine. Highly recommend! If you don't have the cash to pay all at once, its a great way to save in advance for a flight and avoid the hefty interest rates that typically come with most credit cards.