With more and more people using their smartphones and tablets to not only browse the internet, but also do online shopping and run important business and life activities, it's a good idea to make your website mobile-friendly. And that includes using mobile popups.
However, Google recently announced some changes around mobile search results in 2017. One of those changes being the mobile friendly tag, which could be taken off of any sites that use "intrusive interstitials."
This has some people concerned about whether or not they should continue to use mobile popups, but fear not! You can still use mobile popups, you just have to do so in a way that complies with Google's new requirements.