Compare:

“What you’re losing in the DVD market, you’re not making up on the paid internet side,” says Fishbein. “Instead of 99 cents a song on iTunes, these guys are doing 10 cents a minute for porn.”

Contrast:

The Mutoscope worked on the same principle as the “flip book.” The individual image frames were conventional black-and-white, silver-based photographic prints on tough, flexible opaque cards. Rather than being bound into a booklet, the cards were attached to a circular core, rather like a huge Rolodex. A reel typically held about 850 cards, giving a viewing time of about a minute.

See also What the Butler Saw

Thus: “what goes around, cums around…”

Pun works on two levels. Hat tip to Alan Patrick 🙂