Ad server

What happens in a fraction of a second

1. The request. A reader loads a page. The ad tag asks the ad server for an ad, saying which slot is asking and passing what it knows: the page, the device, the approximate location.
2. The decision. The server lists every campaign allowed in that slot, then drops the ones whose targeting does not match, whose budget is spent, whose schedule is off or whose frequency cap this reader has reached. From the rest it picks one, by priority, by price or by weight.
3. The response. It returns the creative or, if nothing qualifies, a fallback.
4. The count. It records the impression, and the click if one follows. Those records become the reports and the bill.

Ad server, ad network and ad exchange

• An ad server is software. It serves and counts ads and brings no advertisers of its own.
• An ad network sells your inventory to its advertisers and keeps a share of what they pay.
• An ad exchange runs automated auctions in which many buyers bid for each impression.

A site can use all three at once: its own ad server decides whether a direct campaign takes the slot and hands the rest to a network or an exchange.

Publisher and advertiser ad servers

A publisher ad server manages the space on a site: its slots, its floor prices, what runs where. An advertiser ad server manages one buyer's campaigns across many sites and counts delivery on the buyer's behalf. When the two counts differ, the gap is called a discrepancy, and the contract decides whose count is billed.

What a publisher should look for

• Tags that are easy to place and do not hold up the page.
• A floor price per slot.
• Approval of every creative before it runs.
• A fallback, so an unsold slot is never wasted.
• Reports an advertiser can read without asking you.
• If you sell direct, a way for advertisers to book and pay without you.

Hosted ad servers run the infrastructure for you. Self-hosted ones cost nothing to license but leave the servers, the updates and the security to you.

How Pyrobid works as an ad server

Pyrobid is a hosted, white-label ad server with the sales side built in. You create slots with a floor price, place one tag, and advertisers book those slots in a portal carrying your brand. Campaigns that clear your floor share a slot in proportion to what they bid. Every creative waits for your approval, impressions bill only once the ad has been seen, and an unsold slot falls back to your choice of an Advertise Here card, your own image or the ad code you ran before.