CTV Advertising: What It Is, How It Works and How to Measure It

What CTV advertising actually is

CTV stands for connected TV: any television that gets its video over the internet instead of over a cable or antenna feed. CTV advertising is the ad slot inside that video. It is usually a 15 or 30 second spot that plays before or during a show, a film or a live event on a streaming app, and it cannot be skipped in most cases.

Two terms get mixed up. CTV refers to the device: the television. OTT (over the top) refers to the delivery method: video sent over the internet, which also reaches phones and laptops. All CTV ads are OTT ads. Not every OTT ad is a CTV ad. When a vendor quotes you a price, ask which one they mean, because a phone-screen impression and a living-room impression are not the same product.

What makes CTV different from linear TV is the buying. A cable ad is bought against a channel and a time slot. A CTV ad is bought against an audience, and the platform decides which household sees it, on which app, at what price.

How CTV ads are bought and billed

There are three common routes to the same screen:

• Direct from the publisher. You agree a deal with a streaming service for a set amount of inventory. This suits large, planned campaigns, including live sports.
• Programmatic through a demand-side platform (DSP). You set a budget, an audience and a bid, and the platform buys impressions across many apps in real time. This is the route most brands start with.
• Through the streaming service's own ad tools. Several large services sell self-serve ads on their own inventory.

Almost all CTV is billed on CPM, the price per thousand impressions. You pay when the ad is served, not when someone clicks, because a television has nothing to click. That is the main reason CTV is judged differently from search ads.

Quick arithmetic you can reuse: budget divided by CPM, times 1,000, equals impressions. At a $4.00 CPM, $10,000 buys 2,500,000 impressions. Premium streaming and live content costs more than that, so always check the CPM you are quoted against the placement you are actually getting.

Why brands use CTV: reach, targeting and the full-funnel role

CTV earns its place for three reasons.

• Reach beyond people who are already searching. Search ads capture demand that exists. CTV creates awareness among people who have not yet searched for you.
• Household-level targeting. Audiences can be built from shopping behaviour, interests or your own customer lists, instead of from a channel's general viewers.
• A big-screen, sound-on environment. The creative gets full attention in a way a thumbnail on a feed does not.

The trade-off is that CTV sits at the top of the funnel. It is better at starting the purchase journey than finishing it. If you judge it on same-day sales from the ad itself, it will usually look weaker than a search campaign, which is bidding on the very last step before a purchase.

How to measure CTV without fooling yourself

This is the part most explainers skip. Because nobody clicks a TV ad, the usual click-based reports under-count what CTV does. Use these measures instead, roughly in this order:

• Completion rate. The share of ad views watched to the end. It tells you whether the creative and the placement are holding attention.
• Reach and frequency. How many households saw the ad and how many times. Too few views does nothing, and too many wastes budget.
• Branded search and direct traffic. Does the volume of people searching your brand name rise in the days after a flight starts?
• New-to-brand rate. What share of buyers had not purchased from you in the past year.
• Incrementality. A holdout test: run the same audience with and without the ad and compare outcomes. It is the only measure that separates sales the ad caused from sales that would have happened anyway.

Ask who designs and computes any test, and whether it is written into the contract. That question applies to every vendor, us included.

CTV advertising on Amazon

For brands that sell on Amazon, CTV has one clear advantage: the ad platform and the store are connected. Amazon DSP can buy streaming TV inventory and match it to shopping signals, and the resulting purchases are attributed inside the same reporting environment, so you can see which sales followed an ad.

Here is what one real book of Amazon DSP business looks like. This is the whole portfolio, not CTV alone: across 30 advertisers in July 2026, reMKTR ran 78.4 million impressions at a $4.00 CPM, delivered 6.04x return on ad spend, and recorded 57,137 attributed purchases at a blended $5.49 cost per acquisition. 20.1% of those purchases came from shoppers new to the brand. Those figures are portfolio-wide and show what DSP delivers across formats. They are not a promise for any one account, and they are not a CTV-only benchmark.

What this should teach you is to set each format its own goal. A streaming TV line is there to reach new shoppers. Judge it on new-to-brand rate and on lift in your searches and Sponsored Products, and judge your retargeting lines on return. Sponsored ads and DSP are two separate systems, and they are best read together: a streaming TV line often shows its effect as extra branded searches and Sponsored Products sales, not as sales on the DSP report itself.

A checklist before you buy CTV

Run through these questions with any platform or agency, including us:

• What exactly am I buying: which apps, which devices, live or on-demand?
• Is the CPM quoted for the placement I will actually get?
• What audience will see the ad, and how is it built?
• Are the ads delivered to the television screen, or to every device?
• What frequency cap will be set?
• What is the success measure for this line, and is it agreed before launch?
• Will there be a holdout or lift test, and who runs it?
• What fees sit on top of media, and will I get written notice if they change?

Starting small is reasonable. Run one test flight with a clear goal, read the result against that goal, and then decide whether to scale.

Who CTV suits, and when to wait

CTV suits brands that already have search and shopping campaigns working, want to reach new customers, and can wait longer than a few days to judge the effect. It also suits brands with a strong video or lifestyle story to tell.

It is usually too early for a brand still fixing its listings, its search term reports or its profitability per order. Fix those first. Search ads are cheaper to test, and they show results the same week. reMKTR runs Amazon DSP, including streaming TV, as a managed service, and is part of Full Circle, which has managed $500M+ in Amazon revenue across 100+ brands. You can find out more at remktr.com.