OTC sellers charge between 3% to 15% depending on a lot of factors.
Why? Can't you always buy BTC instantly with <insert service here>?
Try doing that routinely as part of a business process with instant liquidity, large sums, and/or without getting bank accounts shut down.
#BlockRiot is the home of the blockchain in the fediverse. #cryptotwitter is exiting stage left. @bitcoinhackers.org is great for the Maximalists. The rest of us can land here!