Learn how to use them? Really? My God. With each passing day I add another stupid comment to the list of reasons why Bungie does what it does. Because of simple minded idiots that is. I've done the numbers on 3oC, before the nerf. It was about 10%. That's one exotic per 10 coins. Lately I've been noticing 1 drop for every 15 coins. So the drop percentage for them is lousy. So don't come in here with your "Learn how to use them" comment like it's rocket science. Or are you going to post instructions like: Buy Coins--->Go to your inventory--->Press Square to use coin---> Kill Ultra--->Get nothing--->Wait x minutes--->Repeat from step 2. By the way the 10% or less I'm mentioning is my personal experience. It's RNG after all.