In marketing, a sub-publisher is a third-party that acts on behalf of the original publisher, owning traffic that larger publishers buy and sell to advertisers. Advertisers are unlikely to deal directly with sub-publishers, as they remain a third party. Instead, advertisers work solely with the network that trades with sub-publishers. Understanding this process can help advertisers know which third party owns the traffic they are buying.
Sub-publishers are important in digital advertising because they expand the reach of advertising campaigns by providing additional traffic sources. They allow larger publishers to access a broader audience without directly managing all traffic channels. This helps advertisers reach more potential customers and optimize their ad spend by tapping into diverse and often more cost-effective traffic sources. Additionally, sub-publishers facilitate more efficient ad placement and campaign management by acting as intermediaries between publishers and advertisers.