I heard at one time Sears made more money on their charge card than they did on the merchandise.
However, I know few stores that offer their own charge cards these days. Dillard's might. Many of them use GE.
I actually use credit on most of my projects for materials if my cash is below a threshold to cover overhead and payroll. Many projects have some form of interest on money in the bid. This is true when I consider buying materials, doing the work then billing 30 days net. Many of my commercial clients pay in 30 to 35 days consistently.