They spent a year-and-a-half going through the site’s subreddits, promoting /r/SandersForPresident on posts about politics and liberalism. By mid-April, they had reached about 6,000 subscribers, enough that they thought they could start reaching out to Sanders’s office to show that there would be support if he ran.

“Bernie Sanders has said that he wasn’t going to run unless there was some sort of upswell, some demand for it. We wanted to be leading that,” said Fredrick. “I think every two days we were emailing his office saying ‘Look, we added another 200 people. See, there’s something going on here.’”

Sanders announced at the end of that month that he was going to run. First, Sanders announced that he was going to run in an interview with USA Today—and then made that announcement on the subreddit, which ballooned to 40,000 members in just a few days, according to RedditMetrics.com. Fredrick says they gain 10,000 new members roughly every three weeks.

The subreddit has more than 850 new submissions and 3,000 comments every day, according to Fredrick, and it requires nearly constant moderation. Since June 30, there have been more than 48,000 moderation actions—such as removing posts and banning users—taken on the subreddit, according to Alex Stigler, another one of the community’s moderators.

The numbers are impressive, but winning the Reddit primary is worth exactly zero delegates in the real Democratic primary. Instead, the organizers hope that their online efforts will translate into support when it comes time for voters to cast ballots that count.

“In terms of literally turning Reddit support into real-life support, this has been a tiny struggle for us,” said William Godfrey, another subreddit moderator and Grassroots for Sanders member (and the structural engineer). “The inertia of inaction for a lot of our subscribers, both on Reddit and other social-media channels, is large and difficult to overcome.”

Godfrey says that to encourage redditors to participate in real-world events (or donate money), they give them “flair”, or little badges next to their username, if they verify they attended certain events or participated in certain fundraising drives.

“We have tried our best to gamify Reddit,” said Stigler. “If you provide proof that you had gone out and ‘Chalked the Block’ [an event that the subreddit hosted in August to encourage supporters to write about Sanders in sidewalk chalk in their neighborhoods] for Bernie Sanders … then you get a flair promotion.”

The subreddit also raises money directly for the Sanders campaign (Grassroots for Sanders does not solicit or accept donations themselves). Since the subreddit launched, they’ve raised more than $300,000 dollars from more than 12,000 individual donors, and organize occasional "moneybombs," where they encourage as many people as possible to donate in a short time frame.