Man, people are really butthurt with bitcoin around here. You gave him the best answer of all and all you got was downvotes and a sympathy comment from me... ;)

From a practical standpoint (which is literally what he asked for), using a bitcoin as the sole method of payment is likely to artificially limit your potential customer-base. Bitcoin isn't widespread enough where most consumers can be expected to utilize them for payment. You may create a phenomenal web service, only to see it fail because people can't figure out how to pay for its use.