How can we make Xonotic more popular?

Discuss below.

riveting

I think the most obvious move is invite friends to play with you.
I've already made my 2 brothers play with me, and a friend of mine will likely try it out this evening.
If each player invites another, you effectively double the playerbase. 
If each invitee then invites another player, you increase the playerbase by 50%.
The percentage decreases in each succession if each new player only invites one person, but the number of players itself will keep increasing. And the more people we have the stronger this invitation effect will be.

Seo and PPC can help the xonotic to become popular and social media can also help to become popular.

Small thing you can do: Add Xonotic as "non-steam game" to your Steam library (in case you're using steam).  That way you kinda "spread the word" without much effort. If you have a lot of friends on Steam some might at least look it up, when they see you playing xonotic so much. I even added some pretty screenshots to my Profile. So some people who see my profile might check it out that way. I don't know how much it actually helps but i mean.. why not?

yell at strangers on the street

yell at strangers on the street

one problem: no one really can pronounce the name let alone remember it xD

yell at strangers on the street

Why yelling at strangers when you can simply wear your own custom Xonotic T-shirt (or sweater, cap...) in public

Or a Xonotic mask...

Apply for Jehar's Organgrinder and duel a friend (or an enemy) on Tastyspleen stream.

How about a snowball scheme of blackmailing people?
Like so:
I blackmail you to play xonotic regularily and have fun doing so while you got to blackmail at least 2 more people into doing the same.