It's not hard to make money doing 4 rooms and a hall for 139.99. Most of the time you'll get 3 bedrooms with less than 100 ft of open carpet a bigger living room and a hall. He's not a bottom feeder if you ask me just playing his odds.
How many Extreme or Xtreme carpet cleaning, Best Carpet Cleaning etc. businesses can you think of? Probably too many to count. Stainmaster is a common name in the cleaning industry.