Eh? Pringles cans aren't mostly air, except in a technical sense due to the spaces between the chips.

Different products in different stores, I guess.

Here, and in every other American city I've lived in for the last 20 years, the tall can of Pringles is 50% air.

Do a quick web search, and you'll see hundreds of people complaining about it.

I once complained to the soap company, and got the expected response: They're sold by weight, not volume.

Your posting history indicates that you're not in the United States, so perhaps store shelf space isn't as valuable where you live.