This whole thing is silly. US carriers don't differentiate by method of payment other than for perhaps IDB and downgrades and not even then for the most part.

The term for a ticket not paid for with cash (or equivalent such as CC) is defined by DOT as a "zero dollar ticket."

ZDT's are as opposed to employee, industry and other freebies or close-to-freebies. Those are part of the carrier's operating structure in the same way that employers may choose to subsidize a cafeteria or whatever.