It reminded me of Ryanair's recent addition of a Captcha image to their site, presumably to stop competitors scraping all of their flight prices. They did what Ryanair would, of course, do in this situation: they figured out how they could make money out of it. So after you've selected your dates and destination, you're taken to a screen where you need to enter a Captcha image in order to proceed. But in order to display the words, you first need to click on a button that plays you an advert for a third party brand.
I think most of us are accustomed to and accepting of adverts that we know support otherwise free services, from commercial TV to YouTube. It's part of the contract we enter into when we choose to consume such content. But monetising what is a security measure on your own site? Really?
Aptly enough, I was shown an advert for a popular headache remedy.
Hat tip to @brucelauderdale for the Ryanair thing.