(AP Photo/Paul Sakuma, File)

Slate on Monday announced a new subscription model that it wants to be super sure you know is not a paywall. Called Slate Plus, it keeps most content available for free, but offers subscribers bonuses such as online chats with reporters. The subscribers will pay $5 a month or $50 a year. The bonuses also include discounts or special seats at Slate events and early access to some articles.

"It’s not a paywall," David Plotz, the editor of the online magazine, wrote in a post announcing the service -- twice.

"Our model is Amazon Prime, which just keeps on adding benefits," he wrote. Amazon Prime, which started as a membership program that offered free shipping on most orders for an annual flat fee, has added new features including streaming video and an e-book lending library since its inception -- and only raised the price once in nine years.

Readers may remember that this very outlet, The Washington Post, was bought by Amazon.com  founder and chief executive Jeffrey P. Bezos last year. But not every publication owned by what was then The Washington Post Co., now Graham Holdings, was part of the deal. Some properties, including Slate and Foreign Policy, were left out.

It's no secret that media outlets have struggled to figure out how best to monetize their content -- arguably, that's what led to The Washington Post's sale in the first place. And Slate, like many sites, has primarily relied on advertising since its inception as one of the earliest online only outlets nearly 18 years ago.

"And while advertising remains central to our success, we think we’d be better off if we were less dependent on it," writes Plotz. "We also think it’s important to give readers a stake in the journalism they value."

Slate is far from the first online media outlet to give a subscription model a try, but many including The Post and the New York Times use a paywall that kicks in after a set number of visits per month to encourage regular readers to sign up.

In fact, Slate tried out a more traditional subscription model along those lines in the late 1990s, before the outlet was sold to The Washington Post Co. by Microsoft in 2004.  But perhaps the most direct analogue to Slate's new set up is Talking Point Memo's membership program, which is known as TPM Prime.