What is an Insertion Order (IO)?

An Insertion Order (IO) is a commercial document or buying object that locks media-placement terms between an advertiser (or agency) and the other side: flight, budget, inventory, rate, formats, GEO, creatives, reporting, and payment. In print it was a literal order to insert an ad in a given issue. In digital the meaning is the same: obligations before the campaign runs — not the status of a single conversion.

The short query “what is IO” in Russian search usually means iOS or IoT. This article is about an Insertion Order in advertising (including the IO object in DV360), not an operating system and not connected devices.

What an IO typically states

Parties: advertiser / agency and a publisher, network, or DSP account.
Flight dates, budget (or impression/click goal), currency, rate model (CPM, CPC, sometimes CPA at the deal layer — not an affiliate payout).
Inventory: domains, apps, deal IDs, formats, viewability, brand safety.
Targeting: GEO, audiences, frequency caps on the buy.
Creatives, moderation SLAs, make-goods for under-delivery.
Billing: invoice, net-30/45, tax, overdelivery limits.

Signing the IO (or accepting it in the platform) is the basis for invoicing impressions or clicks. It is a media-buy contract, not “lead approval.”

Insertion Orders in programmatic and DV360

In programmatic an IO often exists in two forms at once. Outside the platform: an IO/MSA with the seller or a guaranteed/PMP deal. Inside the DSP: an object tree. In DV360 the usual ladder is Advertiser → Campaign → Insertion Order → Line Item → creative. The IO is the budget and flight container; the line item is what bids for the impression (targeting, pacing, bid). Optimization lives on the line item; the IO sets the spend ceiling and dates.

Programmatic guaranteed and some PMPs require an IO in the UI before the deal takes volume. Open auction can run without a PDF, but teams still create a budget IO in the DSP — otherwise there is nowhere to hang the cap on spend.

What an IO is not: hold and offer cap

The catalog already has hold period and offer cap. People mix them with IO because all three involve “agreements and money.” They are different objects.

Hold is a pause after a recorded conversion, while the network validates the lead and withholds payout. A hold does not buy media or reserve inventory.
Offer cap is a limit on paid conversions on an offer (day/week/affiliate). It cuts result volume on the advertiser/network side, not impression budget in a DSP.
Insertion Order limits and terms of the media buy (spend, dates, inventory). An IO can end while the offer cap is still open, and the reverse.

They coexist on one launch: a DV360 IO for $10,000 / 14 days; an offer with a personal cap of 50 leads/day and a 14-day hold. Hitting the cap does not close the IO by itself; the IO flight ending does not extend the hold.

Affiliate use of “IO”

In AM chat, “IO” is sometimes any terms file: payout, GEO, allowed traffic, caps. Legally that is network terms or an insertion order in the loose sense of “a service order.” For bookkeeping, split media IO (DSP/publisher) from offer terms (payout, hold, cap). In incent and large direct deals a real IO with the advertiser is still signed — budget, source bans, fraud penalties — but hold and cap remain separate clauses, not synonyms of the title “IO.”

What you reconcile against

An IO invoice is reconciled to the DSP (impressions, eCPM, spend), not to approved conversions in the tracker. The tracker answers “which conversions came from this traffic”; the IO answers “how much media we bought and at what rate.” Spend gaps between the UI and the IO invoice are a seller dispute (under-delivery, overdelivery, viewability). Conversion gaps are a network dispute on postback and hold — not on the IO.