An online ad significantly taller than the 120×240 vertical banner.
Skyscraper ads are tall — very tall — with heights often ranging from 500 to 800 pixels (and widths often ranging from 120 to 160 pixels). For a long time there was no standard sizes to which buyers and sellers adhered. This made skyscraper ads the province of large, well-branded sites that could sell custom advertising packages.
The IAB has since announced standard sizes for skyscraper ads. The standard skyscraper is 120×600 and the wide skyscraper is 160×600. With standards in place, skyscraper ads became more common at advertising networks.
Skyscraper ads are often called skyscraper banners, although some examples have mimicked the look of a banner by using a combination of ad buttons and text.