I tend to think in the same direction.
If a seller accepts credit cards I get the feeling that it is all about the money instead of passion for the things he does.
That is an interesting, and I believe wrong, assessment. Some customers demand the ability to pay with plastic. And, while it would be nice to be able to tell them that you don't because you are passionate - passion don't pay the rent.
When I had my gallery - heck even now - my credit card facilities consisted of one of those old mechanical CC imprint machines.
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Others have talked about the the cost that accepting places on the merchant.... There is also a cost on accepting cash.
A business that deals with cash is more prone robbery. Having your day's cash taken more than makes up for the 1-2% loss to the CC companies.
There is more paperwork when you take cash.... If you deal with a lot of cash, bank deposit slips insist that you list how many bills of each denomination are in the deposit. I can tell you that at the end of a long hectic day, counting how many $5s, $2s, $10s, etc you are depositing and then adding them up is no fun.
If you have employees, then one bad employee can cost you way more than the CC fees.
If you are in a small town, and if it's common to take local cheques - one bad cheque can cost more than a weeks CC fees.
I am passionate about what I do, I take plastic, and I like that when someone does pay with plastic all I have to do is make sure that the amount deposited matches the amount in my sales record.