Ad buying option in which ad placements may appear on any pages on sites within an ad network.
In run-of-network advertising, advertisers generally give up say over placement in return for low rates and broad reach. Ads may be placed randomly in unsold, less valuable portions of sites within an ad network.
Run-of-network buys are similar to run-of-site buys, except the ads appear on many sites instead of an individual site.
see also: Digital Marketing Tools
Display Advertising Stats 2017: SEMrush Study
SEMrush (September 13, 2017) sponsored
The Network Buy
ClickZ (November 16, 1999)