If you’re within two years of achieving a lifetime status, you might want to consider it in your calculations — for example, you might choose to take a UA flight over a slightly more convenient option on another carrier in order to lock in lifetime status faster. The reason that i use an (admittedly, arbitrary) two-year cutoff is that the uncertainty continues to mount the further out you go. Someone who is traveling 50K miles a year — a not inconsiderable amount — will take 20 years to hit one million. Even if they’re halfway through that journey, you’re still talking about planning for 2035, with no idea what the airline industry might look like then.

Nor do I recommend a mileage run just to achieve lifetime status. Spending your weekends flying back and forth, at considerable expense and wear-and-tear on your body, between SFO and SIN, does not seem to be justified by the rewards achieved.

In my opinion, most travelers should ignore the lifetime programs and make their flight choices as if lifetime status doesn’t exist.