It's not all chump change, and there are consumer benefits to buying with a credit card (not debit card - which is an immediate electronic transfer).
People often use credit cards for the rewards. Business card holders can accrue rewards very quickly by using credit cards wherever accepted. If the merchant adds a fee that increases the price of the goods and offsets the benefit of reward programs. You could expect to see a decline in certain corporate card use. (Many reward programs ring in at the rate of 1% or less, often as low as a penny or two per thousand.)
Many of my clients are corporate invoices. I once had someone pay a $10,000 invoice by Amex just for the points. At 3% that was $300 out of my sale - or with this new fee would be $300 added to their bill. Merchant fees and associated costs are a real expense and it can have a chilling affect on many customer profiles. There are sales that might not happen if the client did not have the ability to finance it with their card - or if the cost were to increase because of retailer's charging extra for card use.
The economic environment in my opinion is poised for decline. It's not just new fees from retailers, or new transaction fees from credit card companies and banks. There is an ever escalating tax burden as well. Her in Massachusetts cities and towns have been allowed to start assessing their own local sales taxes. On a recent truck rental I had to pay 6.25% MA sales tax, plus 7% city sales tax. If there were a 3% credit card charge as well - that's an extra cost of 16.25% before I even drive off the lot. Now consider my fuel price is $0.39 /Gal higher thanks to taxes, and if I return the truck empty and the Rental agent bills me for the gas - I even end up paying
sales taxes on the gas taxes! I pay double the standard toll rates for commercial vehicles, and all that before I do my state income tax at 5.25% and my Federal taxes at 28%. If I decide to put any money in a savings account the state taxes the 1.5% interest I earn at 12% and the Feds want to raise their rate to 30%.
Let's not forget that the IRS now tracks all credit card merchant revenues with required 1099-K filings, and you have to separate out the CC payments from your gross revenues when filing your income tax returns.
Given the level of required filings, reporting, and taxation - maybe all purchases/payments should just go to the government and then they can toss us back 20% to scrape by on.