Homepage takeovers are "spectacular" ad units displayed for a day on a publisher homepage. Different types of ad units may be used or combined for page takeovers:
out of box ad units
With homepage takeovers advertisers have a 100% share of voice on the homepage as no other ad is shown.
Homepage takeovers are not sold on a CPM basis but sold for a day and may cost from $400,000 to $700 000 on some websites with huge traffic like Facebook, YouTube or Yahoo and between $200,000 and $300,000 on media websites like ESPN or The New York Times.
Day or session capping is often used for limiting annoyance of intrusive homepage takeovers.
Homepage takeovers are often used for branding campaigns and for products or services with no segmented targets as all visitors are exposed. It is often used for product launch or movie and TV show release.
Homepage takeover are sometimes considered as a waste of advertising budget as it does not use the countless targeting possibilities of digital advertising.
Some examples of homepage takeover ads:
A Prudential homepage takeover on New York Times allowed users to see the front page of the newspaper from the day they were born.
YouTube showcases his homepage takeover: