Glossary
Ad tech, in plain English
Every term explained twice: what it means, and why it matters if you are selling your own ad space rather than handing it to a network. The ones people ask about most have a full guide.
Pricing and money
CPM
Cost per milleThe price of one thousand ad impressions. A $5 CPM means the advertiser pays five dollars each time their ad is shown a thousand times.
CPM is the unit you sell in when you sell directly. Setting a floor CPM is how you refuse demand below the price you think your audience is worth, which is the single most important number on your rate card.
CPC
Cost per clickThe price an advertiser pays each time someone clicks their ad, regardless of how many times it was shown.
CPC shifts performance risk onto you: if your audience does not click, you do not get paid, even though you delivered the impressions. For direct deals, selling on CPM is usually the better trade for a publisher.
CPA
Cost per acquisitionThe advertiser pays only when a user completes a defined action, such as a signup or a purchase.
CPA moves nearly all the risk to you and makes your revenue depend on the advertiser's funnel and their reporting of it. It is common in affiliate arrangements and is the least publisher-friendly of the three main models.
eCPM
Effective cost per milleTotal earnings divided by impressions, times one thousand. It converts any pricing model back into a comparable per-thousand figure.
eCPM is how you compare a direct deal against network revenue honestly. A CPC or revenue-share arrangement can look attractive until you calculate what it actually earned per thousand impressions.
Full guide ›Floor price
Floor CPMThe minimum CPM you will accept for an impression. Bids below it are refused.
A floor is how you stop your inventory being sold cheaply. It is also the mechanism that lets a closed-loop portal work: you set the floor, your advertisers bid above it, and nothing sells below your number.
Full guide ›Rate card
Your published prices for each placement.
Most publishers never build one because they have no data on what buyers will pay. Selling directly for a few months gives you exactly that data, which is something a network relationship never will.
Full guide ›Affiliate marketing
Being paid a commission for conversions you refer, rather than for the ad space itself.
Affiliate income depends on someone else's funnel converting and on their honest reporting of it. Selling the placement directly pays you for the audience you delivered regardless.
vCPM
Viewable CPMCPM calculated only on impressions that met the viewability standard.
If an advertiser asks for vCPM pricing they are asking you to absorb the risk of your own layout. Know your viewable rate before agreeing to it.
Full guide ›Inventory and fill
Impression
Ad impressionOne instance of an ad being served to a user. The basic unit of inventory.
Impressions are what you are selling and what your plan is priced against. Worth knowing whether a platform counts served impressions or ad requests, because the two differ and only one of them is inventory you can actually sell.
Ad request
Ad callA call from a page to an ad server asking for an ad. Not every request results in a served ad.
Some platforms price on ad requests rather than impressions, which means you are billed for calls that returned nothing. Check which one your plan counts before comparing prices between vendors.
Fill rate
The percentage of ad requests that were answered with an ad. A 60% fill rate means four in ten requests returned nothing.
Unsold inventory earns zero, which is why almost every publisher running direct sales also keeps a network underneath as fallback. Direct deals fill first at your price, and the remainder falls through rather than being wasted.
Passback
FallbackWhen an ad server has no ad to serve, it hands the slot back to another source rather than leaving it blank.
This is what lets you run your own portal without giving up your network. It stays in place as the passback, so your direct deals fill first and anything unsold still goes to the network.
Full guide ›Remnant inventory
Ad space left unsold after direct campaigns have been allocated.
Remnant is what networks are genuinely good at monetising. The mistake is treating a network as your whole strategy rather than as the floor underneath your direct sales.
Direct sold
Direct dealInventory sold by the publisher straight to an advertiser, without a network or exchange in between.
Direct deals earn substantially more per impression than programmatic, and they build a relationship you own. A publisher with fifty direct advertisers has an asset; a publisher with a network tag has a traffic source.
Full guide ›Waterfall
Daisy chainDemand sources are called one after another until one fills the impression.
The classic setup is: direct campaigns first, then your best network, then progressively lower-paying fallbacks. Your own portal sits at the top of that chain, which is exactly where the highest-paying demand should be.
House ad
An ad for your own products or content, used to fill inventory that has not sold.
House ads are better than blank space and better than a low-paying network fallback for promoting your own newsletter or shop. Most ad servers let you set them as the last resort in the waterfall.
Full guide ›Make good
Additional free inventory given to an advertiser when a campaign underdelivers.
Worth knowing before you promise impression volumes you cannot guarantee. Selling by date and placement rather than guaranteed impression counts avoids the problem entirely for most small publishers.
Selling and process
Media kit
A document describing your audience, traffic and ad options, sent to prospective advertisers.
The media kit is where deals go to die. By the time a PDF has been emailed, read and replied to, half of interested buyers have moved on. A live portal replaces it with something that can be acted on immediately.
Insertion order
IOThe contract between publisher and advertiser specifying what is being bought, when, and for how much.
IOs are standard at large scale and pure friction at small scale. For a few hundred dollars a month, a self-serve portal replaces the whole document.
Full guide ›Self-serve advertising
A system where advertisers buy placements themselves through a web interface, without contacting a salesperson.
Self-serve is the difference between an Advertise Here page that collects emails and one that collects money. It is also the single most expensive add-on at most established ad servers.
Full guide ›White label
Software sold to be rebranded and run as though it were your own product.
For a publisher this means your advertisers register on your portal, see your logo and your name, and never learn which vendor built it. The relationship stays yours.
Full guide ›Multi-tenant
One software installation serving multiple separate customers, each seeing only their own data.
This is what makes a white-label ad server affordable. You get an isolated, branded environment without anyone running a server for you alone.
Ad server
The software that decides which ad to show in a given slot and delivers it.
This is the core piece. A white-label ad server does the same job but runs under your brand, so advertisers see you rather than a third party.
Full guide ›Ad tag
Zone tagA small snippet of HTML or JavaScript pasted into your page that calls the ad server and renders the ad.
Pasting a tag is the entire technical requirement for most publishers. No rewrite, no plugin, no developer, and you can nest your existing ad code inside it as the fallback.
Zone
PlacementA defined ad slot on your site, with a size and position, that advertisers buy against.
Zones are what you sell. Naming them clearly and setting a sensible floor on each is what turns a vague sponsorship enquiry into a campaign someone can start without asking you a question.
Targeting and data
Targeting
Ad targetingRules that decide which users see which ad, based on attributes like location, device, browser or time of day.
Targeting is what turns one ad slot into several sellable products. The same placement can be sold to different advertisers in different countries at different prices.
Geo-targeting
Serving ads based on the user's geographic location.
Essential in any regulated vertical, where an advertiser may only be licensed to promote in specific places. It is also how you sell the same slot several times over to advertisers in different markets.
Dayparting
Ad schedulingRestricting when ads run, by hour or day of week.
Useful for advertisers whose business has hours, and a straightforward way to sell a premium slot more than once without over-serving your audience.
Contextual targeting
Choosing ads based on the content of the page rather than data about the individual user.
Contextual is having a renaissance as third-party cookies decline, and it is the natural strength of a niche publisher. Your whole site is context an advertiser wants.
Full guide ›First-party data
Data you collect directly from your own audience, such as registrations or newsletter signups.
First-party data is the durable asset as tracking gets harder. It is also something you can only build if you own the advertiser relationship rather than renting it.
Third-party cookie
A cookie set by a domain other than the one being visited, historically used to track users across sites.
The long decline of third-party cookies makes network and programmatic targeting less effective, which quietly raises the relative value of selling your own inventory directly.
Frequency capping
A limit on how many times one user sees the same ad in a given period.
Frequency caps protect your reader experience and make campaigns perform better, which makes renewals more likely. Worth setting even when the advertiser has not asked.
Programmatic
Programmatic advertising
Automated buying and selling of ad inventory through exchanges, typically via real-time auctions.
Programmatic maximises fill and minimises effort, at a price. For a niche audience it usually pays a fraction of what a relevant advertiser would pay directly, because the auction cannot see why your readers are special.
RTB
Real-time biddingAn auction held in the milliseconds while a page loads, deciding which advertiser gets the impression.
Worth understanding mainly so you can tell it apart from what you actually need. Running your own portal is a closed loop: you set a floor and your own advertisers buy above it, with no external exchange involved.
Header bidding
A technique where multiple demand sources bid simultaneously before the ad server is called, rather than in sequence.
Header bidding is a way to squeeze more out of programmatic demand. It solves a different problem from selling directly, and it is worth knowing that it does not help you at all with an advertiser who simply wants to buy a banner from you.
SSP
Supply-side platformSoftware publishers use to sell inventory into programmatic exchanges.
An SSP is for selling into the open market. It solves a different problem from selling to advertisers who already want to reach your specific readers.
DSP
Demand-side platformSoftware advertisers use to buy inventory programmatically across many sites.
Named here mostly for completeness. If your advertisers are individual businesses rather than media agencies, they are not using one, which is precisely why they end up emailing you.
Quality and trust
Viewability
Whether an ad was actually visible on screen, rather than merely loaded. The common standard is 50% of pixels in view for one second.
Viewability is what advertisers use to argue your inventory is worth less. Placements above the fold and in-content generally measure better, which is a good reason to price them higher.
Above the fold
The part of a page visible without scrolling.
Above-the-fold slots have higher viewability and command higher prices. This is the simplest lever most publishers have for justifying a premium placement on their rate card.
CTR
Click-through rateClicks divided by impressions, expressed as a percentage.
CTR is the number advertisers ask about most and the one that varies most by creative quality, which is largely outside your control. Useful to report, dangerous to guarantee.
Brand safety
Controls that keep an advertiser's ads away from content they consider damaging.
When you sell directly, brand safety is a conversation rather than a blocklist. That is an advantage: you can tell an advertiser exactly what your site is, which no exchange can.
Ad fraud
Invalid trafficFake impressions or clicks generated to extract money from advertisers, usually by bots.
Fraud is one reason advertisers distrust unfamiliar inventory. A direct relationship with a publisher they can identify is the oldest and best defence against it, which works in your favour.
Creative
Ad creativeThe actual banner, video or text an advertiser wants shown.
Letting advertisers upload their own creative, subject to your approval, removes the step where you have to chase them for a file and resize it yourself.
The terms are simple. The money is not.
Knowing what a passback is matters because it is the mechanism that lets you sell directly while your network keeps what you do not sell.
Start free trial14 days free. Your existing ads keep running. Cancel anytime.