I use Square for credit/debit sales at farmers markets I do. It's been great—I have a very small number of transactions so it allows me to accept CC without a merchant account. The startup was a little rough—I was an early adopter and they had trouble managing growth and getting readers out to folks who had signed up. It took about 6-7 mos. to get the thing, but I think they've managed their backlog and things are running much more smoothly now.
It's been easy to use and haven't had any problems using my iPhone 3G with it.
thanks for the replies and insight, everyone! am into my 2nd week of using square, and its working quite fantastically! recently, they dropped the additional 15 cent fee for swiped cards...now its just 2.75% when swiped. with my type of business with running tabs for customers for a few days while they're attending or competing at events, its really helpful. received a reply from square the other day...i was asking if they have a means of "storing" a customers card on the reader so they can return after a few days and pay off their tab with the credit card "stored" in the reader. not available yet, but said its a good idea and keep an eye out for it possibly in the future. so, for now, i'm using one of the old-fashioned machines that imprints the card, get the customer's contact info, and then swipe the card at the end of the event. its all good!
the coffee hound
It's the credit card companies themselves that have rules against charging minimums, or adding like $.50 to any credit transaction. At least that was my understanding. It could be regulated by each state, but I know Visa, Mastercard, Discover, and Amex have different rules about it. Here is a good link.
Now Keith may be right as well, and you should check with your state too.
Keith E said:
Many states, as I am aware, make it illegal to have a minimum purchase requirement or "convenience" fee for credit card purchases. Check you local laws Nicholas.