In the old days, when a blogpost got picked up ("slashdotted"), I'd see heavy but steady traffic for days. These days, I see frequent "spikes" of traffic that last for only a few minutes, which then decays. It's how fast that spike decays that's interesting.
The spikey nature of traffic comes from social-networking. People's Twitter and Facebook update several times a minute. When something gets posted at the top, it'll scroll off the bottom a few minutes later. When somebody with a lot of followers links to my blogpost, I'll see a spike of traffic for as long as it stays visible, with traffic decaying quickly as the tweet scrolls downward.
