You're being obtuse. If the point of contention is that a user's transactions might not be mined - your point is redundant. I've settled thousands of value transfers on the Bitcoin network, and have never had a transaction that didn't confirm. Additionally, if the nature of your business is such that this risk was nonetheless unacceptable, Bitpay and Coinbase will happily insure the confirmation risk for free, if you use their payment gateways. I'm certain that whatever this confirmation risk is, it's far less than the risk of a chargeback or receipt of a counterfeit dollar.