What an absolutely brilliant & simple move by Square. POS register systems are a huge, costly market and this is an incredibly attractive option, esp at that price - talk about disruption! Nice job guys!
Groupon charges 1.8% + $0.15 per swipe for Visa/MC/D, Amex varies.
Square charges 2.75% + $0.00, so the
transaction amount breakeven point is $15.80
and Groupon is cheaper for amounts > 15.80,
but Square is cheaper for amounts < 15.80
Not that Square isn't disruptive in other ways.