Right. Ordering stuff over SMS isn't that great an idea. There's going to be a lot of back and forth - what size do you want, is it OK if your flight has a change of planes at DFW, do you want anchovies on the pizza? Sending an order for a bag of groceries via SMS is going to take a lot of typing.

Processing the order is currently manual. You're back in the call center era. For the back and forth, you'd probably be better off using voice. As in, the customer calls the service on the phone.

The big advantage of web ordering is that the user gets to browse the catalog and select. They can find out if it's in stock before they order. The order gets captured correctly and automatically. There's one central service for buying, and it's called Amazon.com.