How to work out connected TV advertising return on investment

What to take away

Connected TV advertising return on investment is the incremental profit your streaming campaign generates, divided by its total cost, expressed as a percentage or a ratio.

Work from incremental revenue, not total revenue, or the figure flatters the channel.
Include media, creative, ad tech and measurement fees in the cost line.
Agree the calculation method with finance before the campaign goes live.
Set a target return that reflects your margin, not a generic industry benchmark.

Define the return before you count the revenue

Return on investment compares profit to cost. For connected TV, the profit is the gross margin on sales the campaign caused, not the revenue it sat beside. If your gross margin is 40% and the campaign drives £50,000 of incremental sales, the profit is £20,000. A team spending £10,000 would see a 100% return on that basis.

Return on investment example

£50,000incremental sales
40%gross margin
£20,000profit
100%return

Finance teams will want the same definition every quarter. Write it down, sign it off, and keep it with the media plan. The cost and budget guide for England sets out the cost categories you will need to mirror in that definition.

Build the cost line properly

Media spend is the obvious cost, but it is rarely the whole picture. Add creative production, platform or ad server fees, verification, and any measurement or attribution contract. A campaign with £30,000 of media may carry another £6,000 of production and technology, which changes the return materially.

Full campaign cost breakdown

£30,000Media spend
£6,000Production and technology

Pricing structures affect how those costs behave. Fixed CPM deals, auction buys and outcome-based arrangements each shift risk between buyer and seller, and the pricing models in England article explains which structure suits which objective.

Estimate incremental revenue

Incremental revenue is the sales you would not have made otherwise. Compare exposed and unexposed groups, or use a holdout region, rather than comparing this month with last month. Seasonality, promotions and competitor activity all move sales independently of your campaign.

For example, a retailer running a £20,000 campaign might see £60,000 of sales in exposed postcodes against £45,000 in a matched control. The incremental figure is £15,000, not £60,000. At a 40% margin that is £6,000 of profit, a 30% return.

Set a target you can defend

A target return should come from your own margin structure and alternative uses of the budget. If a proven search channel returns 150%, a connected TV campaign returning 30% needs a strategic reason to proceed, such as reach or brand building.

Economic conditions change what counts as acceptable. The Office for National Statistics publishes Gross Domestic Product data that planners use as context when advertising budgets tighten or loosen.

Check your claims and creative

Any performance claim in the ad, including implied returns for the viewer, falls under the Consumer Protection from Unfair Trading Regulations 2008. Keep substantiation for every claim on file.

Creative format rules matter too. The IAB UK mobile creativity guidance covers safe areas and legibility that translate directly to connected TV screens, where text is often read at distance.

Agree the measurement window

A 7-day window will show a higher return than a 30-day window on the same campaign, because early responders concentrate in the first days. State the window in every report.

Separate new and existing customers

Sales to existing customers still carry margin, but they are not incremental demand. Split the two groups so the return figure reflects genuine growth.

Use a repeatable checklist

Confirm the return definition with finance and date it.
List every costmedia, creative, technology, measurement.
Choose a control group or holdout before launch.
Fix the attribution window and keep it constant.
Subtract baseline sales to isolate incremental revenue.
Apply gross margin, not revenue, to get profit.
Divide profit by total cost to get the return.
Recalculate monthly and note what changed.

Common questions

Should return on investment use revenue or profit?

Profit. Revenue overstates performance because it ignores the cost of the goods sold. Using gross margin keeps connected TV comparable with other channels.

How long should the measurement window be?

Long enough to capture delayed purchases, typically 14 to 30 days for considered purchases. Whatever you choose, apply it consistently across campaigns.

What return should a first campaign target?

There is no universal figure. Set a floor from your margin and the return available elsewhere, then treat the first campaign as a test of that assumption.

Do platform-reported returns count?

They are a starting point, not the final number. Platform figures often lack a control group, so verify with your own holdout or a third-party measurement source.