Buying through an agency
Not the agencies directory — this is about the doors an agency (or its own trading desk) actually buys through: an account on a DSP, a private deal with a publisher, or a sales house taking the insertion order. See /agencies for the companies you can brief instead.
Looking for an agency to brief?
That is a different list: the agencies directory names companies you hire to plan and run a campaign for you. This page is about the mechanics once someone — you or an agency — is doing the buying: which account gets opened, and on what terms.
Which channels usually fit
An agency buys whatever channel its client's campaign needs — there is no channel an agency-style buy rules in or out. What changes is the door: instead of opening one self-serve account per seller, an agency (or its trading desk) more often opens one account on a demand-side platform and reaches many publishers' ad spots through it, or negotiates a private deal directly with one seller's sales house.
How you'll actually buy
Three doors, and they are not exclusive: opening an account on a demand-side platform to buy across many publishers at once through an auction or a private deal; going direct to a seller's own sales house for an insertion order; or working through a reseller who already holds a relationship. Which one fits depends on the client, the budget and how much control over placement actually matters for the campaign.
What you'll be asked for
An application, not a card
Opening a DSP account is rarely instant — most require an application or a sales conversation, and a stated minimum spend is the exception rather than the rule on the platforms tracked here.
An insertion order, for a direct deal
A sales house's own booking paperwork — terms, dates, the rate agreed — for anything bought outside an auction.
Client authorisation
Buying on a client's behalf usually means the seller or platform wants to know who is actually paying, before or alongside the campaign.
What to check first
What the platform actually is
A demand-side platform, or a hybrid that also runs supply — the listing's kind says which, and a buyer only ever opens an account on the demand side.
How you get in
Self-serve, an application, or a signed contract — read off the listing rather than assumed from the platform's size.
How many publishers it actually reaches
The publishers figure on a platform's listing is how many name it in their own ads.txt — the sample a buyer is actually shopping across.
Demand-side platforms, by publishers reached
The platforms an agency or a trading desk opens an account on to buy across many publishers at once — the same ones the exchanges directory lists, ranked here by how many publishers' ads.txt name them.
Sellers whose own sales team runs the deal
Sellers whose buying method is recorded as a sales team rather than a console — a call, a media kit, an insertion order — the door a planner uses for a direct, negotiated placement instead of a DSP auction.
Questions
Is this the same as the agencies directory?
No. The agencies directory lists companies you can brief to plan and run a campaign. This page is about the accounts and deals that buying itself runs through, whether you are doing it yourself or through one of those agencies.
Do I need my own DSP account, or can I buy from a publisher directly?
Either is real. A DSP account reaches many publishers' ad spots at once through an auction or a private deal; buying direct means going to one seller's own sales house for an insertion order. Bigger, more targeted buys tend toward the first; a single high-value placement tends toward the second.
What does opening a DSP account cost?
Most of the platforms tracked here state no minimum spend at all — a stated one is the exception, not the rule. What it actually takes is more often an application or a sales conversation than a payment; the listing's entry route says which.