Does that strategy actually work for them ? I might consider myself in minority here. Just ask for some curiosity facts.
The numbers in the article were fairly clear, despite abysmal clicks they would see results.
2) If I had to guess, I'd bet that tactic works well on a less experienced and technically unsophisticated crowd. You might not be the target audience for some dumb popup, but a less experienced user who sees some flashy warning message might just take the bait.