What’s the point of a "Read full story" button?

I've noticed a lot of news websites, particularly on mobile, sometimes will cut off their story with a button you have to click to see the rest of it. I can understand why they'd do this if they wanted to make you pay for the rest of the article or shove an ad in your face, but sometimes the button just shows the story and does nothing else.

Here's an example of an article that does this on mobile.

To me, this seems like a really bad user experience. Making someone tap a button to continue browsing your site seems like a good way to lose their interest. Is there some hidden value in this interface design choice? Or does it serve some unrelated purpose (perhaps for analytics on user engagement?)