I started sending out emails to gaming sites and blogs this morning. We've had a great response so far. Right now a lot of our traffic is coming from Reddit:
I've begun hosting a second server that may or may not be temporary, depending upon how many of the new people stick around:
Whatever happens, I'll be happy to transfer savefiles between servers later on. Our only hiccup so far is one that we expected: the use of BYOND icon functions makes the server chug when there are lots of people creating new characters. Nothing we can't solve by hosting a few more servers in the short term.