just read it myself,to me this works for business that will get the customer buying extras,if you go to a restraunt you will buy drinks and maybe return,if you have your windows cleaned that's probably it,no more no less as the lady who owns the oven cleaning business found out once its cleaned that's probably it for 12 months or so if someone wants to use groupon to have there windows cleaned then to me they are not the kind of customer to build a business on,just my opinion