Ooooh... honestly, I'd seriously rethink the no-online-billing thing...
It's very 10 years ago... as a potential client I would look at that and wonder if you were truly in-tune with what's going on today? If you aren't running your business with the basics of today's technology then how can I be assured you really understand my viewers/needs or today's buyers in general? (The people I hired you to write to)
I can pay my credit cards, electric bill, cable bill, phone bill, and of course do pay all my data center fees online ... If I can't pay them, I can at least see the invoices online and then call with a CC# or mail a check. But to be totally offline? -- that'd raise some red flags.
But that's just me, I might not be your target market, in which case my opinion is of little value to your situation.

Bailey