Honest question: What's the value of this service? It seems you seem to suffer with any volatility: the exchange rates would be a constant drain on your net worth. Without any volatility, the service basically does nothing.

There doesn't seem to be any benefit, other than maintaining a minimum or maximum balance on your account. Perhaps this is useful for merchants who want to accept BTC without the risk of holding an excessive amount of BTC. Hmm. I might have just answered my own question.