Interesting article outlining Google’s position on interstitial ads on mobile web.
As sites continue to try to force visitors into app usage, it’s clear that the use of banners, overlays and interstitials are on the rise in mobile web.
As Google outlines in this post, here are a few examples of good overlay usage:
Interstitials that appear to be in response to a legal obligation, such as for cookie usage or for age verification.
Login dialogs on sites where content is not publicly indexable. For example, this would include private content such as email or unindexable content that is behind a paywall.
Banners that use a reasonable amount of screen space and are easily dismissible. For example, the app install banners provided by Safari and Chrome are examples of banners that use a reasonable amount of screen space.