I was wondering if anyone has firsthand knowledge of UA tagging the profiles of people who fly obvious mileage runs. I know that runs aren't against UA's rules, and that UA is not Delta, but I imagine that UA would want to give fewer special mileage promotions and the like to people who it knows work the system.

Perhaps this is done less explicitly, by calculating someone's overall $/mile and then deciding promotions and other treatment based on that?