"Soylent" is a good example. They regularly post about their elaborate IT infrastructure. Based on their sales volume, they do about two transactions a minute. One shared server could handle their transaction load. They could get a low-end hosting account from Hostgator, use one of the six shopping cart programs Hostgator supports, and lay off most of their computer staff.

(Soylent doesn't even make the stuff. That's outsourced to Jasper Products in Joplin, MO.[1])

[1] http://www.jasperproducts.com