I know it's been hit before ... but there is 50 mile grace on the upgrade for the total one way distance - so for me to fly SJU-MIA (1,045) requires 2 stickers ... but SJU-ORD (2,072) requires 5.

In the latter example, you kind of feel like you're getting ripped off a little bit since you're using a sticker for ostensibly only 72 miles.... but most probably have many more stickers than me and don't care too much.

Sincerely, - jdburns11