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In forcesince 1 Sep 2023 · Global · Klaviyo

Klaviyo holdout groups need 400,000 profiles

Klaviyo ships native holdout groups free, and they are the methodologically correct way to answer whether your email caused the revenue. They require at least 400,000 total profiles, apply across all channels at once, allow only one active holdout, and the percentage cannot be changed once set.

Who this applies to

Every brand under 400,000 profiles has no incrementality measurement available at all. Above it, you get one account-wide, all-channel holdout, never per flow.

What to do

  • If you clear 400,000 profiles, turn it on. It is free and it is better than any estimate.
  • Choose the percentage carefully, because it is immutable.
  • Below the threshold, be honest that attributed revenue is an estimate, and do not present it as causal.
  • Note that the specialist incrementality vendors, Haus, Measured and INCRMNTAL, do not cover email as a channel.

What happens if you do not

Not enforced. It is a product gate, and it is the reason most brands cannot answer the most important question they have.

Source

  • Klaviyo, Global holdout groups
    Published 1 Jan 2026Read it

Related

History of this page

  • Added.
Added 28 Jun 2026 · Updated 28 Jun 2026 · Last verified 1 Aug 2026
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