Mine shows ads but doesn't play audio. Plus the ads are just for like their Citi credit card, relatively unobtrusive.

Tangentially, I recently came to the unfortunate conclusion that it's just not worth my time to get gas at Costco if there's a line, especially if I'm out and about on a lunch break. The gas is good and it's much cheaper, but if it's like 6 cars back and a 15-20 minute wait, I actually save money by filling up elsewhere and just getting back to work sooner.