obviously building something, slapping some guns and a minigame on it and hosting a dedi isn't the way to do it, you've got to invite some friends over so you can get it up to 3 players. If the gamemode doesn't blow ass, then you'll certainly see a steady flow of players come in.
It's why I love the RTB friends system. When my friends see me hosting they join in and see whats up. That's how my incredibly boring Chernobyl [WIP] would average 10 players.