Quartz tweaked its site design Sunday, mostly in ways even careful readers are unlikely to notice. But one change stands out on mobile. If you follow a link to an article — say, from Twitter or Facebook — and scroll down a bit, you’ll see the story fade out and a button that says “Read Full Story”:

If you tap that button, you…read the full story. But if you just keep scrolling instead, you’ll first see an ad:

And then a list of other story headlines:

On the surface, it seems like an odd hurdle to put in front of the reader. She’s already tapped a link to that piece, after all; why assume that she wants to do anything other than read it?

I asked Quartz executive editor (and ex-Nieman Labber) Zach Seward that question:

@jbenton We're showing it on the first story for side-door visits, mostly thinking in-app browsers, trying to do two things:

— Zach Seward (@zseward) June 1, 2015

@jbenton 1) keep some people who would have otherwise left by showing them other options; and 2) improve metrics on the ad below it.

— Zach Seward (@zseward) June 1, 2015

The rise of social distribution has meant the rise of one-off visits — readers who come in the side door and exit right back out to the social platform from whence they came. No matter how good your content, some number of readers are going to abandon your story a few grafs in; why not give them some other options and throw in another ad impression while you’re at it? The bet here is that you’re annoying readers less with that extra tap than you are luring them into another article.

In a way, you can think of this as a natural response to responsive design. On desktop, article pages often have a main article well with one or more sidebars, filled with shiny things to click. On mobile, those shiny things tend to get pushed down below the article text — which, if the article’s lengthy, can be many screenfuls of scrolling away. This Quartz model puts the alternative actions closer to where the reader might see them.

(Note too that this marks the end of infinite scroll on mobile at the site that first popularized it in news circles. Now, after the end of a story, you get a list of headlines to pick from — not the full text of the next story.)

To give credit where it’s due, Zach mentions that the inspiration here is The New York Times, which started doing something similar on its mobile article pages last year for side-door non-logged-in mobile visits. I spoke with Alex Hardiman — then the Times’ executive director of mobile products, now its vice president of product — about it at the time, in an interview where we were talking mostly about something else. She described it as an attempt “to be a little more deliberate in plugging up dead ends” — to try to extend those quick side-door visits into something more.

“It’s an experiment — if we place that button there, does it cause confusion?” she said when we spoke last spring. “Is it a useless extra tap? Or can we surface other pieces of content that will be of interest to the reader?”

Such a button could also be useful as a story metric. Are some stories better than others at getting people to tap through to their conclusion? Do certain subjects or certain headline styles — or, god forbid, certain writers — consistently lead people to abandon ship pre-button? Ebook publishers have long been interested in good data on where people stop reading; it makes sense that news organizations would be too. If you’ll excuse the Seinfeld metaphor:

@zseward @James_daSilva Also a potentially useful story-performance metric — tap percentage is basically the story’s spongeworthiness.

— Joshua Benton (@jbenton) June 1, 2015

@zseward @James_daSilva When your writers start making sure to get that juicy quote “above the button,” you’ll know it’s having an impact!

— Joshua Benton (@jbenton) June 1, 2015