1) Everyone seems to update at the same time. I look at my friends page, and there's no change for hours, days sometimes. Then I come back a few hours later and find something like five posts from 3 people, and this happens all the time.
2) Project Upstream. Anyone who's encountered a fish-bot, or been trouted (or salmoned, or cohoed) should be familiar with this. If not...then go look it up, you'll likely be amused. Or you could just visit
themissinghat, and look at their profile. Either way, it'll explain the phenomenom.