An ad network is a platform designed to serve as a mediator between online publishers and advertisers. Ad networks generally collect unsold or remnant ad inventory from different publishers and supply this pool of impressions to advertisers at a lower rate than the direct sales by the publisher. Ad networks take a more strategic approach and lean towards offering their advertisers more exclusive deals at premium prices. Many mobile ad networks support a broad spectrum of formats, starting from banners to native ads. There are others who focus on specific formats, such as video. Some ad networks also provide a platform for advertisers to sign-in and manage their campaigns. A managed service also exists where account managers administer a consultative approach. They also ensure that the campaign runs at optimal levels. Ad networks have become indispensable monetization element of the online advertising ecosystem. They act as a commercial and technical intermediary between advertisers and publishers. On the technical level, integrations are often provided for the supply-side to offer their inventory. The demand-side is offered to activate and monitor campaigns. Ad networks facilitate payments and transactions. Without ad network solutions to pull demand, publishers would have to negotiate deals with each advertiser.