Ooh, I hate these. Maybe I hate these even more than the ones that appear immediately.
I don't know how most people react to these popups. I think there are stats since I guess that people who put these on their websites also put all sorts of trackers, but for me, it is often a signal to simply close the tab and never come back.
The reason is that it completely breaks my focus. I am reading an article, browsing stuff, and find it interesting. Then the popup pops. Now, I am distracted and start to think. Is it that interesting? What am I doing here? Then tell myself I have better things to do than stay on a website with aggressive popups.
And if the content really is good, I will just close the popup and continue reading. I mean, I am in the middle of a good article right now, I have better things to do than filling some form.
Don't worry, if your content is so good that I want to subscribe, I will find your button, you don't need to shove it in my face.