20+ ads per campaign: CPA 6.8% better than with 1–2 ads
Commentary byROASArchiveOur analysis, not theirsAn NP Digital chart shared on LinkedIn found that campaigns with 20+ ads had a 6.8% CPA improvement compared with campaigns running 1-2 ads.
The data covers 50 companies advertising on Google and Meta.
The gain grew with ad count up to about 11-15 ads, then stayed roughly flat.
- 3-5 ads: 2.3% CPA improvement. 6-10 ads: 4.1%.
- 11-15 ads: 6.6%. 16-20 ads: 5.7%, a small dip.
- 20+ ads: 6.8%, which works out to only 0.2 points better than 11-15 ads (6.8 minus 6.6).
- The overall effect is modest. Even the largest group improves CPA by less than 7%.
The change
Before
The baseline group is campaigns with 1-2 ads, set at 0% improvement.
After
Groups with more ads per campaign were compared against it: 3-5, 6-10, 11-15, 16-20 and 20+ ads.
Our reading: why it likely worked
Our interpretation, not the advertiser's claim.
- More ads give the algorithm more chances to find a version that fits each audience, which lowers cost a little.
- The flattening after 11-15 ads suggests extra ads add little once there is enough variety.
- Companies running 20+ ads may also have bigger budgets or teams, which could explain part of the gap.
Caveats: This is an aggregate study across 50 companies, comparing groups rather than running a split test, so it shows a link, not a cause. Spend, verticals, time period and how CPA improvement was calculated are not shared. We saw it as a chart reposted on LinkedIn, dated April 2026.
How to run this in your account
- Hypothesis
- If we raise a campaign from 1-2 ads to around 10-15 distinct ads, then CPA will fall slightly because the platform has more options to match to each viewer.
- Primary metric
- CPA
- Guardrails
- Spend per ad
- Frequency
- Creative production cost
- Who should try it
- Advertisers running only 1-2 ads per campaign with enough budget to give new ads spend. It probably won't pay off if making extra ads costs more than a 5-7% CPA gain is worth.
Questions
How many ads should I have per campaign?
In this NP Digital data, CPA improved as ad count rose to 11-15 ads, then barely changed.
20+ ads (6.8%) works out to only 0.2 points better than 11-15 (6.6%).
Does adding more ads lower CPA?
A little, on average. Campaigns with 20+ ads showed a 6.8% CPA improvement over those with 1-2 ads across 50 companies.
Is there a point where more ads stop helping?
This chart suggests so. The 16-20 group did slightly worse than 11-15, and 20+ was about the same.