>>27529454Eggs don't seem to track your distance traveled very well. It seems to just take your present location every 5 minutes, draw a line to your location 5 minutes ago, and award you distance equal to the length of the line. So, if you're walking in a loop around a short park, or something, you don't get much distance at all. You're better off just walking far away in a straight line and then turning around to come back.
Also, from what I've seen, longer distance give you more candy for the pokemon that hatch out of them, in addition to those pokemon being rarer. Can anyone corroborate?