Brands ask us this on nearly every first call, usually hoping for a single number they can put in a plan. Ten. Thirty. Whatever the last agency said. The number you want depends on how much you can afford to spend finding things out, and you can work it out yourself in about two minutes.
The napkin formula
To judge a creative, you need to spend enough on it to see a pattern. Our rule of thumb is ten purchases’ worth of budget per creative, at your target cost per purchase. Ten is an arbitrary line, and ten purchases prove very little on their own, but that much spend will usually separate the obvious losers from the ads that deserve more money.
Next, decide how much of your monthly budget is for testing. We usually suggest a fifth to a quarter, with the rest behind ads that are already working.
Three worked examples
All three brands are hypothetical. The method is the part to keep.
- Small: $5,000 a month in ads, 25% for testing, so $1,250. With a target cost per purchase of $25, each creative needs about $250. That’s five creatives a month.
- Medium: $20,000 a month, 25% for testing, so $5,000. With a target of $40, each creative needs $400. That’s twelve creatives, after rounding down from 12.5.
- Large: $100,000 a month, 20% for testing, so $20,000. With a target of $50, each creative needs $500. That’s 40 creatives.
The large brand has a different problem from the others. Forty a month is more than most teams can brief, review and learn from, so the limit moves from budget to attention. Twenty tests you learn from will beat forty you only glance at.
Twelve creatives doesn’t mean twelve ideas
This is where people overspend on production. The medium brand above doesn’t need twelve separate concepts. A sensible month might be four concepts with three hooks each. Hooks are cheap to make and quick to read. A new concept costs more and can tell you something bigger, such as whether a whole audience or message has been sitting there unused.
We like at least one test in four to be properly different from everything else in the account: a new angle, a new kind of creator, a format you’ve never tried. Variations on a winner give you small, dependable gains. The odd ones are how you find the next winner before the current one wears out.
Signs your number is wrong
- Too low: one ad has carried the account for months and nobody wants to touch it.
- Too low: costs are creeping up on your best ads and you have nothing ready to replace them.
- Too high: most ads get a handful of purchases each, and every result looks like a coin toss.
- Too high: your team is approving videos it has no time to watch.
One thing the formula can’t see is where the money goes once a test starts. Ad platforms tend to pick a favourite early and starve the rest, so a creative with a $400 allowance might get $40. Our piece on building a testing loop covers how to set tests up to avoid that.
If this is your first go
Take whatever the formula gives you and halve it. Running six creatives properly teaches you more than running twelve in a rush, and you’ll find out how quickly your team can brief, review and read results. With us, finished videos arrive in about 7 to 10 days, so place the order well before the month you want to test.