Some article websites (I’m looking at msn.com right now, as an example) show the first page or so of article content and then have a “Continue Reading” button, which you must click to see the rest of the article. This seems so ridiculous, from a UX perspective–I know how to scroll down to continue reading, so why hide the text and make me click a button, then have me scroll? Why has this become a fairly common practice?
I think there’s more to it than just farming data. The goal of many websites is to trick people into actually reading their content, which you generally only manage to do for long form content if you can get people to read “below the fold”. That’s the reason many articles start with a huge picture and a few paragraphs of useless fluff, because you want people to lock in by taking the extra step and scrolling down.
I can also think of a more profit oriented reason: by loading the rest of the article down the line, websites like archive.org don’t capture a full, free version of the article, and the “three free articles” system becomes harder to bypass.