Bernie Sanders has 23 field offices spread out across Iowa that will all be chugging along next week to bring voters to the caucuses, but the most important hub for winning the critical state may actually lie in the internet’s top generator of memes and funny cat pictures.

The Vermont Senator has crafted an active online hub on Reddit, where the SandersForPresident subreddit has more than 160,000 subscribers and has one of the most active userbases on the site. That’s especially important on Reddit, where user votes determine what links appear on the front page — and Bernie’s supporters send positive stories there almost daily.

The SandersForPresident subreddit has been chugging along for months, with users sharing stories about Bernie’s recent surge and posting his policy statements. But it’s become more than just a discussion ground for Millennials. In the weeks leading up to the Iowa caucus, it has also become a functioning arm of the campaign’s get-out-the-vote efforts.

At the top of the page, in a large red banner, is a link to a YouTube video from the Sanders campaign explaining how to caucus. There are others organizing voters, helping them register and find caucus sites.

Bernie Sanders is getting a surge of volunteers in rural Iowa from @reddit https://t.co/gWdpP0CkRD by @hunterw pic.twitter.com/uev90NoV4J — Yahoo Politics (@YahooPolitics) January 28, 2016

While Bernie Sanders has 23 field offices in Iowa, the campaign may be making up for it with the de-facto virtual field office on Reddit. As Yahoo! Politics noted, some groups have taken their work beyond Reddit, coming to Iowa from across the country to work in rural areas that might be far from the campaign’s actual field offices.

“On Medium, [campaign volunteer Alexander Rhodes] explained that the majority of the Reddit volunteers would be used for canvassing and knocking on the doors of voters who are thinking about caucusing for Sanders. Once volunteers arrive in Iowa, the Sanders campaign is helping them find accommodations at the homes of Sanders supporters. “We need your help. We’re pretty well-off in the big cities, but those make up only a number of caucus events. There are dozens of other caucuses throughout the state, and those regions are currently significantly understaffed. This project is intended to bring much-needed reinforcements into the understaffed rural areas of Iowa.”

The story itself turned into a bit of a self-perpetuating success on the SandersForPresident subreddit. A link to the story was posted this week, and the subreddit’s moderators pinned a comment to the top sharing information on how others can sign up to help. As the story hit the front page, that meant tens of thousands of views and a greater chance that some might join the effort to help elect Sanders.

The site has already shown how much support it can leverage — just two days before the story was published, users hit the $1 million mark for donations throughout the campaign. A total of $50,000 was raised just during this week’s town hall meeting alone.

But grassroots efforts might be the site’s most important contribution. As FiveThirtyEight noted, turnout will be pivotal if Bernie Sanders hopes to win the state.

“Voters who say they will ‘definitely caucus’ favor Clinton 45 percent to 36 percent over Sanders, but Iowa Democrats who say they will ‘probably caucus’ favor Sanders by a margin of 47 percent to 37 percent. If Bernie Sanders hopes to pull off this upset, he will need those ‘probable’ caucus-goers to turn out near 2008’s historic levels, when turnout in the Democratic caucuses (235,000) almost doubled 2004’s (125,000).”

If Bernie Sanders can win in Iowa and hold onto his large lead in New Hampshire, then the SandersForPresident subreddit could end up being an engine to push him along in the string of more difficult states that will follow, starting with South Carolina. While the efforts of one website shouldn’t be overstated, its achievement already reflects what will likely be key to Sanders winning the nomination — getting his core group of Millennial supporters to move beyond slacktivism and actually show up at the polls.

[Picture by Joe Raedle/Getty Images]