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Half banner
HTML banner
A banner that includes Hypertext Markup Language file, the code also
used to create web pages.
HTML menu banner
Another name for a drop-down menu that appears in a banner.

IAB
Abbreviation for Internet Advertising Bureau.
The IAB is a global nonprofit association which measures the effectiveness
of advertising on the Internet, along with promoting voluntary online
ad standards for both publishers and advertisers.
Impression
A single time a banner is shown to a visitor.
IMUs
Abbreviation for Interactive Marketing Units.
Term for the new dimensions of banner ads by the IAB.
Initial load
The first file segment of a banner that initially downloads for the
viewer to experience almost immediately, so the viewer doesn't have
to wait for the entire banner to download.
Interstitial
A banner that appears in a separate browser window while you wait
for a Web page to load. Interstitials are in various sizes, and are
more likely to contain large graphics, streaming presentations, and
special features not found in conventional banners.