Because nobody else bit Don's bait:
A vampire, a werewolf, and a ghost walk into a bar.
The bartender says, "(To the vampire and werewolf) We don't much care fer yer kind around here; you have ta go. But we do serve spirits"

I Am Legend was a better film than I expected. Better by far than the old Chuck Heston version. I really liked Will Smith's acting.
The "abandoned NYC CGI was pretty spiffy. Using the USS Intrepid's SR-71 as a golf tee was a hoot.(Not giving that away, it was in the TV commercials)
On the other hand, I just saw an alternate ending to it that was so much better than the one they used, I wanted to thump whoever made the choice with a stick.