Pops still work and will continue to do so IF used properly. I strongly advise you steer clear from networks with shady practices that do not cap the traffic / visitor or allow their publishers to integrate more than 1 pop per visitor per 24h.
It is common knowledge that pops will 99% of the times hinder the UX therefor the results they offer will be lower than other formats and that is mostly because of the greed that both publishers and ad networks share. And yes, it is a harsh statement but I've been in this industry for more than 12 years now and I know first hand how media buyers and agencies treat pop traffic and it's sources.
I personally recommend you do small tests to reputable companies first and see how that works for you. If your ROI is where you want it to be then you're all good.
Best of luck!
It is common knowledge that pops will 99% of the times hinder the UX therefor the results they offer will be lower than other formats and that is mostly because of the greed that both publishers and ad networks share. And yes, it is a harsh statement but I've been in this industry for more than 12 years now and I know first hand how media buyers and agencies treat pop traffic and it's sources.
I personally recommend you do small tests to reputable companies first and see how that works for you. If your ROI is where you want it to be then you're all good.
Best of luck!