Pop-up and interstitial dialogues are used to generate leads, share offers and discounts, and distribute important information. But if it is not used rightly, you can lose your ranking.

The negative impact of Pop-up and interstitial dialogues

These elements can cause a poor user experience. User experience is the key factor in any website’s ranking.

How to use them effectively?

Let your visitors access your website without any distractions. Let them complete the goal of their choice. It can be getting the information about something or any interaction with the page elements. Let them spend some time or generate any event.

After the interaction, you can show pop-ups and interstitial dialogues. This practice will help you maintain the bounce rate and retain a good user experience.

What Google states about interstitials and popups

Even Google suggests using banners instead of interstitials. Banners take only a small fraction of the screen to grab your users’ attention. Whereas Intrusive interstitials and dialogues are page elements that obstruct users’ view of the content,

Intrusive dialogs and interstitials make it hard for Google and other search engines to understand your content, which may lead to poor search performance. Equally, if users find your site hard to use, they are unlikely to want to visit those websites again, including through search engines.

https://developers.google.com/search/docs/advanced/guidelines/avoid-intrusive-interstitials

About Mandatory Interstitials

Certain sites are required to show an interstitial due to the kind of content they are publishing. For example, a casino site may need to show an age-gate, which is a type of interstitial where the user must provide their age before accessing the content.

Mandatory interstitials are exempted from the guidelines discussed in this document; however, if possible, we recommend that sites follow these best practices:

• Ensure that the content is overlaid with the interstitial. This will ensure that Google can still at least index some of the content and potentially show it in search results.
• Don’t redirect the incoming HTTP requests to a different page for collecting consent or providing data. Redirecting all URLs to a single page will remove all but that one page from search results, as Googlebot can only fetch that page.