Google has warned publishers it is preparing to penalise pop up ad pushers.

Pop Off

Google issued the missive on its Webmaster blog.

"Pages that show intrusive interstitials provide a poorer experience to users than other pages where content is immediately accessible.

"To improve the mobile search experience, after January 10, 2017, pages where content is not easily accessible to a user on the transition from the mobile search results may not rank as highly," wrote Google Product Manager Doantam Phan.

Adapt or be banished

Google says the update is aimed at improving the mobile experience for users. It also advised some ad formats, if used responsibly, will not be affected by the change.

These include interstitials to appear for legal obligations (for example, cookie usage), and banners that use a reasonable about of screen space and are easily dismissible.

Login dialogs on sites where content is not publicly indexable (eg, personal information behind a paywall) are also safe.

Brands and marketers, you have three months to get up to shape or face Google's wrath. Consider yourselves forewarned.