In the US we sign for most transactions that can have a tip.

Typical restaurant flow would be:

1. Server gives you an initial receipt with your subtotal on it so you know how much you owe
2. You give them your card, they charge it the initial amount and give you a second receipt
3. You write in a tip amount (and calculate the new total) on this second receipt and sign it

Our credit card companies don’t require signatures anymore so we don’t have to do this nonsense when we buy anywhere that doesn’t take tips (grocery store, department store, etc.); I assume restaurants just want some sort of “proof” in case you try and dispute the charge later.

True, fuel cost would be the same per flight, but maybe Corkyskog is getting at the airline still coming out ahead with more seats since they would sell more tickets.

Overall that would mean less flights needed to move the same number of people so it arguably does reduce fuel cost in a sense.

(This assumes that people physically take up less space as they lose weight, which, I guess for dimensions like legroom, maybe isn’t the case)

Yep, that’s the 7 pro - I had one, too. It was perfect for me because I never took selfies.