[PQ-7055] Clarify Unique Recipients

[diana-smirnova]

Why are you making this change? (required)

Several customers were confused by /sends/data_series stats because we include a unique_recipients stat for each send identifier, but unique recipients are counted at the campaign level, not the send ID level. This behavior is noted in the /sends/data_series response, but it can also be helpful to document it here.

Related PRs, issues, or features (optional)

• N/A

Feature release date (optional)

• N/A

Contributor checklist

• I confirm that my PR meets the following:
  • I signed the Contribution License Agreement (CLA).
  • My style and voice follows the Braze Style Guide.
  • My content contains correct spelling and grammar.
  • All links are working correctly.
  • If I renamed or moved a file or directory, I set up URL redirects for each file.
  • If I updated or replaced an image, I did not remove the original image file from the repository. (For more information, see Updating an image).
  • If my PR is related to a paid SKU, third party, SMS, AI, or privacy, I have received written approval from Braze Legal.

Submitting for review

If your PR meets the above requirements, select Ready for review, then add a reviewer:

• Non-Braze contributors: Add braze-inc/docs-team as the reviewer.
• Braze employees: Have any relevant subject matter experts (like engineers or product managers) review your work first, then add the tech writer assigned to your specific vertical. If you're not sure which tech writer to add, you can add braze-inc/docs-team instead.

Thanks for contributing! We look forward to reading your work.

[internetisaiah]

hi @diana-smirnova , i'm on the docs team here at braze 👋🏽 is this one ready for review?

[diana-smirnova]

hi @diana-smirnova , i'm on the docs team here at braze 👋🏽 is this one ready for review?

Just need to double-check with the CSM that this docs update is necessary - I'll mark it as a draft for now

[josh-mccrowell-braze]

Hi @diana-smirnova : Just following up about your progress checking in with the CSM about this PR! Thanks!

[diana-smirnova]

Hi @diana-smirnova : Just following up about your progress checking in with the CSM about this PR! Thanks!

Confirmed with the CSM that this update is necessary, the PR is now ready for review!