eCommerce: Not just for product sales?

I met with the sales & marketing director of a large hosted shopping-cart solution yesterday and he asked an excellent question:  With about 70% of small businesses selling services rather than products, how long will it take for SB service companies to leverage eCommerce?

• Attorney's selling chunks of time online?
• Contractors accepting payments online?

or...

• Pay for your haircut before you drive over?
• Your car wash?

And he's a smart cookie, so he suggested the eCommerce platform for SM B's could be easily tweaked to accommodate online scheduling as well.  What would that look like?:

• Go online, schedule your haircut appointment for next Tuesday, pay for it.  That took 284 seconds.
  • You didn't have to pick up the phone.
  • Your stylist (no, not 'barber') didn't have to answer your call
  • You didn't have to make sure you had cash in your wallet when you rushed over (late) on Tuesday.

Slick.

We have some of this right now, of course.  Fandango is a good example, but the opportunity for 1000's of other markets is there.  Waiting.