Businesses have been charging extra for CC for a long time.  The first place I saw it was at a gun store.
Frankly, I feel like it's a way to avoid raising their prices.  I can kind of see it for items like guns that can be pretty competitive on price.  For almost anything else, I think it's just a lazy way to make the 3% without bothering.
I'd like to see businesses charge more for cash and check due to the annoyance factor.  Either the customer doesn't know how to count/be ready to pay or the cashier doesn't know how to make change. 

. Same thing for checks.  However, it's not like I make that many transactions. 
 
On the other hand, many gas stations give you a discount for using their loyalty programs.  AFAIK, there isn't any way to set it up without a CC.  So, kind of odd that one type of business is encouraging CC and others are discouraging it.
Arbitrary business decisions are fun.