Is a cash register too limiting for your business? (After all, it’s a pain to pack up for an off-site show, and there’s no 
electrical outlet for it during your sidewalk sale.)
Is the POS function of your consignment software too onerous to get to, when you’re in the middle of an intake or buyout? (And another terminal means networking issues, or you can’t find the space for more equipment at your counter.)
Or maybe business is booming and you need a way to handle the crowds. Or you want to sell goods or gift cards at a bazaar.
Maybe you need a dongle? Look into the options here on the SBA article about Turning Your Mobile Device Into a Cash Register
Auntie Kate The Resale Expert 
Tara of Born Again posted this experience she’s had with Square over on Facebook, and kindly gave me permission to share it here on my blog:
“I have the Square for another small biz I own. It’s ok but not a replacement for a cc machine and service in a store, in my opinion. It’s locked into a single phone~mine~ so if I’m not at the store and my phone is with me, emps cannot charge a card.
It is also unprofessional. The “receipt” it sends to the customer is lame, and sometimes it doesn’t send it at all (can’t yet figure out why this sometimes happens). I recently went to a little hole-in-the-wall Mexican restaurant and the dude swiped my card on his phone/Square and flashed the screen at me really quick to prove he typed in the right amount…but he could have typed $40 instead of $10 and I really wouldn’t have been able to see it. Anyway, just…no.”
I am looking into which one I want but thanks for the comparison!