Less than 40K. Peanuts are in the top 4. Not many places you can toss the shells and no one yells at you. To draw more fans the concessions need to be more affordable. My family of 3 easily spend $50 on mediocre food.

Why can't every team do this?

Higher than 40k. There could be youth groups, etc. going. 1. Hot dog 2. Hot pretzels 3. Ice Cream in a helmet 4. Nachos

< 40,000. Add two pre-game ticket drawings: 3 fans get to sit in the bullpen; 3 get to sit on the bench. Peanuts have to go to the top of the list for me. They are an integral part of my first baseball memory (see my IC bio). Of course, back then they were served freshly roasted.

Lower on 40,000 and peanuts are dead last