Switching to the M3 method: CPM $50 → $15
Commentary byROASArchiveOur analysis, not theirsAn advertiser moved their account to the M3 method and CPM dropped from $50 to $15. @SamPiliero shared the post from the community where the method is taught, calling it a 70% cut in CPMs.
The poster says ROAS went up too, but gives no ROAS numbers.
- CPM: $50 → $15, which works out to a 70% drop in cost per 1,000 impressions, the "70%" cut @SamPiliero cites.
- ROAS: reported as up, with no figures. Treat this as a claim, not a measured result.
- The poster notes attribution changed between periods, so ROAS is "not apples to apples". They add that Northbeam numbers also improved.
- Not shared: spend, dates, conversions, CPA, platform or what M3 involves.
The change
Before
The account was paying about $50 CPM before the switch. The post does not describe the old setup.
After
The team rebuilt the account using the M3 method, and CPM came down to about $15.
Our reading: why it likely worked
Our interpretation, not the advertiser's claim.
- A CPM drop this large usually means the algorithm is finding cheaper delivery, often from a broader or simpler setup.
- CPM does not depend on attribution, so it is the most reliable number in this post.
- Lower CPM only matters if conversion rate holds. Without CPA, we can't tell how much of the gain reached the bottom line.
Caveats: This is a self-reported before/after with only two rounded CPM numbers, no control, no dates and no spend. The M3 method is not explained in the post, and the poster admits attribution settings changed between periods.
How to run this in your account
- Hypothesis
- If we rebuild the account structure, then CPM will fall because delivery has more room to find cheaper impressions.
- Primary metric
- CPM
- Guardrails
- CPA
- Conversion rate
- Blended ROAS from a third-party or store view
- Who should try it
- Accounts with high CPMs and a complex setup. It probably won't help if CPM is already low for your market, or if the real problem is the offer or landing page.
Questions
Can a new account structure lower CPM?
This advertiser reports CPM falling from $50 to $15 after moving to the M3 method.
No spend or dates were shared, so treat it as one account's experience.
Does attribution affect CPM?
No. CPM is what you pay for 1,000 impressions, so it isn't changed by attribution settings. The poster makes the same point.
Is lower CPM always better?
Only if the cheaper impressions still convert. This post doesn't share CPA, so check cost per purchase before calling a CPM drop a win.