Well, that’s it folks: Twitter is dead. It had a good flight. A short flight, but a noisy one. Sadly, it is now headed the way of Flappy Bird.

So claims the Atlantic in a 1,800-word “eulogy for Twitter” that packs in about 140 characters’ worth of actual evidence. No need to read the whole piece—the fourth paragraph sums it up:

The publishing platform that carried us into the mobile Internet age is receding. Its influence on publishing will remain, but the platform’s place in Internet culture is changing in a way that feels irreversible and echoes the tradition of AIM and pre-2005 blogging. A lot of this argument comes down to what we feel.

At least the Atlantic admits that its case against Twitter amounts to an unsubstantiated hunch. On Wall Street, meanwhile, investors are flocking to downgrade the company’s stock on the basis of selective evidence. Two numbers in particular—the amount of users who log into Twitter each month, and the number of timelines they viewed—have been widely interpreted as indictments of the company’s growth trajectory. Both figures are growing, but their rate of growth has slowed slightly. Twitter will probably never have as many users as Facebook, Wall Street is belatedly realizing. Wall Street hates that.

But Wall Street—along with everyone else who’s down on Twitter because it has “a growth problem”—is making a mistake by comparing it to Facebook. Twitter is not a social network. Not primarily, anyway. It’s better described as a social media platform, with the emphasis on “media platform.” And media platforms should not be judged by the same metrics as social networks.

Social networks connect people with one another. Those connections tend to be reciprocal. Facebook even checks in on you now and then to make sure you’ve actually met the folks who are sending you friend requests. As a social network, its chief function is to help friends, family, and acquaintances keep in touch.

Media platforms, by contrast, connect publishers with their public. Those connections tend not to be reciprocal. One Twitter user may be followed by millions of strangers whom she feels no obligation to follow back, any more than an evening news anchor feels the need to check in with each of her viewers every night at 6. As a media platform, Twitter’s chief function is to help people keep up with what’s going on in the world, and what influential people are thinking and doing at any given time. In that regard, it’s closer to a news service than a social network.

That’s no accident: A turning point in Twitter’s development came when early employees excitedly tweeted about a minor earthquake they’d just felt. And CEO Dick Costolo was the founder of Feedburner, an RSS feed management service that was acquired by Google. Twitter is to news as Instagram is to photography.

Sure, some people tweet privately and follow only their friends, just as some segment of people post publicly on Facebook and allow strangers to follow them. But while those private tweeters may be large in number, they are not the ones who give Twitter its identity.

Here’s what Wall Street needs to understand: Since Facebook is made up of a huge number of roughly equivalent individual users, its volume of “monthly active users” is a reasonable way to measure its growth and scope. Twitter comprises a relatively small number of public figures broadcasting their messages publicly and a somewhat larger direct audience. That makes “monthly active users” a crude metric at best, since one group of users is very different from the other.

To further complicate things, Twitter’s most influential users do not tweet with the expectation that they’ll be heard only with the people who follow them directly. Rather, they treat the platform like it’s a one-way TV interview, using Twitter to break news, to win arguments, to build their brands, to hone their public personas. That’s because they understand that some of their tweets are likely to resonate far beyond Twitter.com and the Twitter app. The photo that Barack Obama tweeted when he won re-election was viewed by tens of millions of Americans who have never used Twitter. Ditto Ellen’s Oscars selfie.

Twitter’s active users then, are only the most easily measured portion of its audience. And the number of timelines people view on the site or app does not capture the service’s vast reach. Even if you’ve never signed up for Twitter, you’ve almost certainly been part of the audience for tweets, whether they’re displayed on television, quoted on the radio, or embedded in an article like this one. Whether you choose to or not, you’re likely to see more in the months and years to come. Yet you won’t show up in any of the metrics Wall Street is relying on to assess its growth.

Yes, active users and timeline views are somewhat relevant to Twitter. They matter because, for the time being at least, direct timeline views by logged-in users are the form of engagement that Twitter can most readily turn into money. Advertisers buy promoted tweets in users’ timelines based on those users’ interests and what they’re likely to be doing at any given moment (e.g., watching Mad Men or the Super Bowl). That’s very similar to Facebook’s business model. And if you visit Twitter.com without an account, you won’t see much. That reinforces the sense that Twitter is useless to those who have no interest in tweeting, and it prevents Twitter from showing ads to nonusers.

Both of these things are likely to change, however. Through MoPub, a mobile advertising platform that Twitter acquired last year, the company can already make money on ads that appear outside of Twitter, on third-party mobile apps. (Think of how Google reaches people with AdSense ads across the Web even when they’re not actively using Google.) Twitter has 255 million active users, but it brags that it can already reach 1 billion iOS and Android users via MoPub.

In the future, Twitter is also likely to find new ways to capitalize on its vast indirect audience. For example, those tweets you see embedded in articles online could come with their own advertisements, analogous to the pre-roll ads that play before embedded YouTube videos. Twitter CEO Dick Costolo hinted as much in an interview on CNBC on Wednesday.

The YouTube comparison is more apt than it might seem. Like Twitter, YouTube comprises two broad classes of users: content creators and viewers. The difference is that you can still get the full YouTube experience if you visit the site without an account. And so YouTube is able to report more than 1 billion “unique visitors” per month—unique visitors being a metric more appropriate to media platforms than social networks.

Don’t be surprised to see Twitter become more YouTube-like, turning its home page into a real-time news platform accessible to anyone, whether they’re logged in or not. That would expand its potential user base to include, for the first time, the majority of Americans who have no interest in either tweeting or curating their own Twitter timelines. If and when that happens, I doubt we’ll be hearing much about Twitter’s growth problem—let alone its demise.