Does anyone know how to get your local events listed on Google Now?

I'm loving using Google Now! on a Nexus 4 I'm using, and I'd love to make it even more useful for people around me. Plus, I'd love to take advantage of what seems like a great marketing tool for local events by having events I'm associated with show up on the local events card.

However - I can't find anywhere that says where they're getting their data from. Facebook? Meetup? Google+ Events? All of those? I expected there to be something on their website about where they get the information from, but I don't see anything. Any advice/insight on that would be awesome.