Suggestion:
Seeing as this topic is currently debating a way to increase online activity for certain reasons, how about this.
Aside from any tournaments;

Create a psn party chat (the type you stay in, even when you go offline).
Invite all active members from to forums, and maybe even all active players online that you come across who dont know about this community, but who seem to be serious about wipeout.

An example: for those who played wo2048 on vita and have the trophies, there was a trophy to complete 210 challenges online. Some requiring you to win. However the game was deserted online and you needed 4 in a lobby to start the game.

I created a group chat and invited players based on trophy stats and recent trophy activity. At one point we had 20-25 people in the chat. Some installed the chat on their phones and tablets, i did this as well. If there was anyone available to play, they would post in the chat and sometimes 10 minutes later we would be playing online.

I think we could easily get 50-100 people in a chat for WOOC.
Might help setting up a tournament in the future too.