What A DRTV Test Really Costs: Do The Maths Before The Media

Most direct-response TV tests that fail were never going to work. They fail on arithmetic, not creative: the airtime cost more per response than a customer was worth. The good news is that you can do the maths before you spend anything.

Start with what a response is worth

Work backwards from the sale. If a new customer is worth £120 in margin and one in four callers buys, each response is worth about £30 to you. That is your allowable cost per response. Anything above it loses money, however good the campaign looks.

In DRTV the only price that matters is the cost per response, and you can estimate it before you book.

Then work out what the airtime buys

TV is priced per thousand people reached (impacts), not per spot. On our 2026 ITV1 data, a thousand adult impacts averages £12.21 in Granada and £14.58 nationally (regional prices). So a £20,000 test in Granada buys roughly 1.6 million adult impacts at average market price, before any negotiated discount.

A worked example

Suppose the test produces half a response for every thousand impacts. That figure is illustrative: real response rates vary hugely by offer, creative and daypart, which is exactly what the test is for. On that assumption:

• 1.6 million impacts × 0.5 per thousand = about 800 responses
• £20,000 ÷ 800 = about £25 per response
• Against an allowable £30, the test pays back with a margin to optimise into

Halve the response rate and the cost per response doubles to £50, and the same test loses money. That is why the allowable figure has to be set before the media is bought, not after.

What moves the numbers in your favour

• Cheaper regions and dayparts. Response audiences are often watching in the daytime, when airtime is better value than peak.
• Negotiated rates. Market averages are a starting point. A buyer who trades response airtime every week should be beating them.
• Spot length. A 10-second spot costs about half a 30-second one, but rarely carries enough information to make someone pick up the phone. Test 20 and 30-second edits against each other.
• Weekly optimisation. Cut what doesn’t respond after the first week and move the money to what does.

The independent buyer’s view

We ask every DRTV client for the allowable cost per response before we talk about channels. If a plan cannot plausibly beat it, the honest advice is not to run it yet. See our DRTV buying guide or send us your numbers.