Pop-ups like that have long been shown to improve conversion rates... at the increase of pissing off people who wouldn't have been a conversion anyway.
What was the last hover ad you saw? Closing it is so instinctual I doubt it even registered. Those people won't remember next time. Annoying people is an evolutionarily stable strategy.
After writing this today, I was reading an interesting (to me) article on building two sided marketplaces, a pop up came up around half way through, didn't feel unreasonable actually as I was feeling value from the contents of the article and it felt likely appropriate moment for them to make the ask.