Mileage programs?

Just got a spam email from Alitalia asking me to join their mileage program.

How do you say “mile” in Italian?

I thought, “Isn’t it strange that the airlines (US and non-US based) all have mileage programs and not kilometer-age ones?”

Turns out the aviation industry is weird.

Outside US, SI is generally used for everything except altitude, distance and speed.

Unless you’re in Russia and China. The measurement units used mostly boil down to matters of convenience it seems.