From 2,997 active users across all lemmy instances at the beginning of June, the number increased to 52,797 by June 30th. Source.
An active user on Lemmy is "someone who has posted or commented on our instance or community within the last given time frame.” Source. That means lurkers are not counted as active users.
We’re really building something here!
From the lemmy.world front page:
Donations If you would like to make a donation to support the cost of running this platform, please do so at the mastodon.world donation URLs: https://opencollective.com/mastodonworld https://patreon.com/mastodonworld