Why was everyone at Mad Hatter on Saturday night?

Question: Why was half the Jewish community at Mad Hatter this past Saturday night?

Potential contributing causes:
1) It’s in DuPont.
2) There’s no cover.
3) It’s so crowded that you don’t really have to dance.

But seriously, how did 4 Jewish birthday parties, a Northwestern party, and a couple smaller groups all end up at the same place? Are we that well-networked?