[klvino]

Generally, a "take-over" is a guarantee from a publisher that all ad slots appearing on a specific page will only deliver ads for a single advertisers for a limited time period, usually a day or two.

Variations on "take-over" exist where you may have a "branded slate" in which the normal framing and background of the site will also be updated to align (and sometimes synchronize) with the "take-over" ads for that day.

You have likely visited imdb.com at some point in time. With so many TV shows and movies premiering throughout the year, IMDB has a higher frequency of "take-overs" than an average site.

The "pop-ups" or interstitials did decrease due to being bad design & bad consumer experience, but have returned and are now overrun with publisher sign-in and privacy/consent interstitials.