There is a clear difference between a milestone and an effort based achievement peen. Milestones are intended to represent longevity and pure continuation in a game. The idea is simply if you keep on plugging you will achieve those things. Spider-man is a milestone peen. It will simply happen. Veteran is a milestone peen.

The job board peens are hybrid peens. A player must be very focused to earn them quickly, but a player using minimal effort (clicking to accept a job when running one of those forums) will eventually earn those peens.

I think milestone peens are cool. They give a “hey, I’ve been doing this for awhile!” reward. They also have the ability to encourage players to look further as to what is available goal wise.