I think frequent exchange participants--as most of the people in this one definitely are--are pretty good about making sure they're matchable on something. I'm also aware of three people who deleted their sign-up because they weren't, or didn't believe they were, matchable.

I gave the mod a list of DW & LJ communities that I thought would be good for promoting this event

I saw your list and thought it looked really good! I can only imagine she either thought that what she was doing was enough, or she wanted to keep the first round small to see how the event went out of the gate.

says that she didn't hear about the event until I made this particular post.

Likewise. I posted a couple times on tumblr, and people who I know follow me and read my page didn't see the post until I spoke to them directly.