As someone who's had to implement one of those nagging popups(and argue with marketing 'growth hackers' about it) I can tell they are unfortunately effective, a

As someone who's had to implement one of those nagging popups(and argue with marketing 'growth hackers' about it) I can tell they are unfortunately effective, and it's more likely to see more of them in future. Everyone is annoyed, but many of those who are annoyed will just follow the instructions and increase the metric of whoever wanted those .