Is it better to paginate a long article or show the entire article on one page?

The following is a side-by-side of the same article. On the left is page one with navigation and on the right is the full article.

Is there data to support that one is better than the other? If so, what makes it better?

The following is an example of the article navigation for a long article.

The user is given the option of just seeing the whole story, skipping to a particular page or going to the next page.

Wouldn't it be easier (read: better) to give the user access to the entire article right away? If the user reads the first page and then decides they want to see the full story, they'll go through a page refresh and be taken to the top of the page with the full story. That can't be a good UX right?

My hunch is this is some sort of ploy to get more clicks on a site, but perhaps I'm missing a real reason why paginating a long article or post might be better.

So, what's the deal?