Most of the project right now are using either discord or telegram for building up a community and might he should do some giveaways(not airdrop), weekly nor monthly quiz,raffle or task so that it could appealing to the new comers to come and to make the old members to stay. And you should follow some suggestion here since some of them are brilliant like hiring a influencer or maybe grab a famous endorser to label out and maximize your product growth and community.