AM/PM mini marts are co-located with ARCO gas stations; ARCO (and AM/PM) are U.S. brands of British Petroleum.
In the late 70s, AM/PM started offering heat-to-eat hot dogs & burgers, and eventually expanded to a wide variety of snack and to go foods, nestled among a pretty respectible condiment bar.
When I first started stopping there, I was living in suburban Los Angeles, and I was delighted I could get burgers or dogs any time of day or night. Those first years, the price point was 2 / $1.00.
30 years later, they are up to 2 / $3, but still a deal. I dove into two spicy hot dogs the other day, much akin to a Johnsonville polish, not natural casings, but a nice snap nonetheless. And of course, I loaded them up at the condiment bar. A nice snack. About 900 AM PM locations in the US West. (Exterior photo from AM PM website).