Not gonna lie, I'm having a very hard time convincing my friends to play this game.
I've tried everything. I want to play this game SO BADLY.
It would be really helpful if you had a recruit-a-friend campaign. If you purchase something, you give an item to a friend, and if you party together, your XP is increased by 50-100%. One purchase by an interested player trying to grasp on to a friend to play with them, give them a bonus by being with you, and spending more time in the game.
The item only works when you're both in the same party. Think of it as a bonding item. The player has a chance to spend time with a friend to teach them the ropes and enjoy the game more.
Since my friends are all playing Animal Crossing and other games, it's going to take something like this to pull them away from it. Please consider an item like this to give more incentive for friends to be together and want to play.