I've noticed that when I paste my site link into my twitter feeds, it generates instant traffic in the form of "guests"onto my site...as in immediately after I tweet. Surely, this traffic can't be real people because it's too quick. If this this traffic isn't robots, then what is it?
Aliens monitor tweets too!?
Seriously though, if it's not real people and it's not bots who would you think it is? I'm fairly sure it's bots - not web cache spider bots, but tweet bots such as tweetdeck etc. ?