Memberships have long been an additional income stream for news organisations, as a way to supplement advertising revenue and even substitute or accompany paywalls for some outlets. But beyond that, they are also a tool for audience engagement and community building.

In the United States, most public media companies, including member stations of National Public Radio (NPR) rely heavily on contributions from listeners.

In the UK, some paywalled outlets such as The Wall Street Journal and The Times and The Sunday Times offer memberships as part of or additionally to their subscriber packages.

The Guardian, which does not operate a paywall, confirmed losses of £69 million for the last financial year, but highlighted an increase in paying members at the end of July. More than 50,000 people are paying between £5 and £60 a month to support the Guardian's journalism, and the outlet's outgoing executive editor of digital, Aron Pilhofer, said the organisation has "started to put some serious effort" behind the membership scheme in the last six months.

So at what point does a regular reader want to become a member and belong to a certain group of people who support, financially or otherwise, the type of journalism produced by a news outlet? And what value do these members bring to a publication and what perks or opportunities are they being offered in return?

Online magazine Slate first introduced Slate Plus in 2014, which then-editor David Plotz described as a "membership programme for Slate's most loyal (and vociferous fans)".

Slate's content on the site has remained free to access, but members paying $5 a month or $50 a year receive additional benefits such as an ad-free version of Slate's iOS app, weekly bonus (and ad-free) segments of the magazine's most popular shows, member-only podcasts and discussions with Slate writers, and early access to columns and longform pieces.

In June 2015, Digiday reported Slate Plus had gathered 9,000 paying members – since then, the number has almost doubled, currently standing at 16,000 members, director of product development David Stern told Journalism.co.uk.

"For one, it's helping us diversify our revenue stream beyond advertising, as a way to monetise the enthusiasm of our most loyal fans who are willing to get their credit cards out and support the journalism we do.

"It looks like it's not going to be a game changer for us in terms of revenue generation, the share of our total margin could be 30-40 per cent or it might max out in a few years to 10-15 per cent, but our expenses around this are not that significant.

"Non-financially, [the membership] creates opportunities for greater engagement between readers and writers, and gives people on both sides of that relationship a feeling of closeness."

Bonus segments of Slate's most popular podcasts, such as Culture Gabfest and Political Gabfest, are "probably the number one driver of subscriptions", Stern added, and listeners are "a smaller group than our overall online readership but they are incredibly interested in receiving more content".

Slate has also developed member-only editorial initiatives, such as its series of so-called 'academies'. The first instalment, The History of American Slavery, contains a nine-episode podcast, essays, book excerpts and a private Facebook group for the audience to interact with the hosts, which Stern identified as a project that "changed the way people thought of Slate Plus for more ambitious journalism".

The magazine's Dear Prudence advice column is also a main membership driver, as members get to ask the host more questions than regular readers and get access to the column's podcast, which is ad-free and twice the length of the free version. Occasionally, Slate invites members to talk about the magazine and its future in open threads on the website and hosts exclusive events, such as parties the company hosted last year in New York and Washington to celebrate reaching 10,000 members.

So how do people go from regular readers to becoming members? Stern explained the conversion rates are highest with people who show loyalty to Slate to some extent, whether they are daily or bi-weekly visitors, fans of a particular column or podcast, or frequent commenters.

"Podcast data is not great, but many of our podcast listeners generally consume every single minute of audio we produce, so if they can get more of it by paying a little bit of money every month, they will.

"Our members are much more likely to be commenters too. They're the smallest group of people, but the conversion rate is highest, with some 10-11 per cent of our commenters roughly having joined as members. It is also high with daily visitors at 3.3 per cent, podcast listeners at 2.9 per cent and Dear Prudence fans at 1.9 per cent.

"What we're trying to do is develop our offering and promoting that to a specific niche within our audience."

On Slate Plus's product team, Stern and a product manager focus on coming up with new benefits and opportunities for the membership scheme, as well as improving the already existing experiences and marketing them to readers.

On the editorial side, the magazine hired an editorial director for Slate Plus last year, who comes up with new content ideas and monitors what gets people to join by conducting regular surveys with both existing and potential members.

"Talk to readers and get a sense of what they want more of. Do the thing that you're already good at and where you're already providing value, but think of how you can provide more value for a subset of your audience who are highly engaged? That's how we've approached it."

This is a two-part series on how news organisations are approaching memberships. Check back tomorrow for a look at memberships at non-profit news outlets The Texas Tribune and The Boston Institute for Nonprofit Journalism.

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