It’s Healthcare Day on Capitol Hill: Senate Republicans are finally revealing their secret Obamacare-replacing bill today. But in the inboxes of many Vox readers, every day has been Healthcare Day for a few months now.

VoxCare is only Vox’s second email newsletter and its first focused on a specific topic (Vox Sentences is an evening news roundup), but so far the daily email is seeing a consistent open rate every day of the week, selling out its advertisements, and even building a community.

“The idea was to give people an update in the late afternoon about the important thing that happened today,” explained Sarah Kliff, Vox senior policy correspondent and healthcare reporter. “We’re not going to give you a link for everything…but we’re going to give you a key insight into what is happening in healthcare today.”

Kliff developed VoxCare — “the only coverage we provide is ~news coverage~” she quipped on Twitter at its launch — in the first few months of 2017 as Republicans started trying to pass tried to pass their healthcare plan. The newsletter has gained traction ever since, especially as mass media has been criticized for focusing too much on the allegations surrounding Russia and the 2016 presidential election and not enough on the Republicans’ healthcare plan.

It does more than just track the tit-for-tat of the national healthcare debate, though: last week, Vox healthcare reporter Dylan Scott told readers of the newsletter how he went for a walk with Senator Lisa Murkowski (R-AK), a Republican swing vote, and provided a transcript of their exchange as the main part of the newsletter. Other times, Kliff has focused on state-level policy issues like Nevada’s dalliance with SprinkleCare. The newsletter also includes a chart of the day featuring a healthcare-related statistic (trends in teenage smoking, for example) and a “Kliff’s Notes” section of curated links at the bottom of the email.

Vox doesn’t talk publicly about open rates or subscriber numbers, but Vox.com general manager Andrew Golis says VoxCare’s following has been tremendous.

“The newsletter has been sold out every day that it has existed,” he said, noting that there are only two spots for ads from a single advertiser. (In recent newsletters, it’s been biopharmaceutical company Pfizer.) “We’re not surprised, but we’re quite pleased that, for folks who are trying to reach the most influential active folks around this topic, this newsletter is the perfect way to do it.”

Who are the people behind the open rate? “We have subscribers on Capitol Hill, people who work in the industry, and people who are just out in the country interested in this, like Obamacare enrollees,” Kliff said. “What helps bridge the gap is that all the groups want to understand what this latest development means…People want the analysis.”

Kliff, who previously worked for The Washington Post and Politico, has been covering healthcare policy since the introduction of Obamacare. She also cohosts Vox’s policy-focused weekly podcast, The Weeds, with editor-in-chief Ezra Klein and cofounder and writer Matthew Yglesias. Balancing the three hours each day that goes producing into the newsletter with her other commitments has made her more creative as a reporter, Kliff said.

“Doing a growing number of things that are not ‘articles on the Internet’ makes me a better reporter. I’m keeping in mind that there are actually people reading these stories who are relying on us for information,” she said. The human interaction comes from a 6,800-member Facebook group associated with the podcast, and emails she receives from VoxCare readers in response to the newsletter. “I personally really enjoy that interaction. It makes my job as a reporter more fun, more varied. I’m hearing a lot more perspectives as I’m experimenting more.”

Writing a newsletter requires a change in tone from writing a regular story, too. “I do a little more referring — like, ‘You might have read a few weeks ago’ — and I think it’s a little bit more of a relationship with the reader,” Kliff said. “For VoxCare, it’s more than a breaking news story of ‘Here is what happened.’ We think our readers are looking for the ‘What does it mean?’ side.”

As with The Weeds’ Facebook group, Golis and others are thinking of ways to transform the VoxCare subscriber base into a more tangible network. “We see really interesting things happening with podcasts and newsletters in which you can build that ongoing engaged community,” he said.

Having a point person like Kliff send the emails — they show up in your inbox as “Sarah Kliff, Vox.com” — doesn’t hurt. “Sarah has interviewed the key players in the space. People have come to trust her over the years from the long time she’s been reporting on this,” Golis said. “Can we take the trust they have in Sarah and connect it…through the Vox coverage?”

After all, if you have a significant number of people tuning in every day for what can sometimes be dry, in-the-weeds healthcare policy issues, something most be going right. “In the news environment we’re in right now, it is not hard to write a daily newsletter on healthcare,” Kliff said. “If we get to a point where the healthcare debate is dying down, we’ll think about how it should exist in a less busy news environment.”