Shared pixel: one website, one business portfolio, two ad accounts

One shared memory at the top. URL rules separate the two cities below it.

Business portfolio · KMCNo learning
Owns the pixel and shares it with both ad accounts.
Lets you share custom conversions across accounts, so both can use them.
Brain 1 · Shared pixel / datasetShared memory
Installed once on the KMC Indy Squarespace site. It tracks every page, Indy and Cincy.
Cincy can draw on the site’s existing visitor and conversion history instead of starting cold.
Ad account · Indy
Its own budget and its own performance history.
Indy custom conversions + audiences
All site events except /cincinnati pages
Campaigns
Brain 2 · Ad sets
Optimize toward Indy conversions.
Brain 3 · Ads
Indy classes and events.
Ad account · CincyWarm start
Its own budget. Account history starts fresh, but the shared pixel doesn’t.
Cincy custom conversions + audiences
URL contains /cincinnati
Campaigns
Brain 2 · Ad sets
Separate learning phase on Cincy’s own spend.
Brain 3 · Ads
Cincy workshops and talks.
Shared
  • One pixel / dataset on one website
  • Site visitor and conversion history
  • Custom conversions, if you share them
Still separate
  • Ad accounts, budgets and billing
  • Account performance history
  • Campaigns, ad sets, learning phases and ads
The main idea
Sharing the pixel means sharing memory, not learning. Each account’s ad sets still learn on their own, and they only aim at the conversions you point them to.
Source material

Meta Business Help Center: About the Meta Pixel, Share a pixel with ad accounts, About custom conversions. facebook.com/business/help