Thats exactly what i thought, but when i first started i couldn`t afford combinations of things so just bought one or the other, so if you wanted to get an Isis crankset for your bike, and couldn`t afford cranks and bb at the same time these would be for you. these adapters could be made very cheaply so you could get new cranks and use them with your old BB until you could afford an Isis one. i suppose the target market would be people on a budget and beginners really. crank puller would get the adapter out too.