BFCM, Agencies, part 2

The pre-BFCM tracking and QA audit for every client store

An ecommerce tracking audit checklist for agencies: install health, order matching, consent by region and an A/A test on each client store before BFCM.

Benchmyrk teamPublished 7 min read

In short

Short answer

  • Audit tracking on every client store before you trust any test result from the season. A test can only be as accurate as the visits and orders it counts.
  • Check four things per store: installation health, how orders match Shopify, consent settings for the client's regions, and internal traffic.
  • Run a short A/A test (two identical arms) on each store you'll test. It checks that the split and the order counting behave before money depends on them.
  • Write the audit into the client's report, with the date and what you found. When a result is questioned in December, that page is your answer.

Who this is for: agency analysts and account leads preparing several client stores for Black Friday testing.

When to do it

When to do it
DateStep
Wednesday, October 21 to Friday, October 23Health, order matching, consent and internal traffic on every store
By Sunday, October 25A/A tests running on stores that will test
Before each real test launchesA/A read; any mismatch explained
Monday, November 16Freeze: re-check health on every store the morning of the freeze
Thursday, November 26 to Monday, November 30Daily health and order checks

Step 1: Installation health, store by store

For each client store, confirm the parts that carry data into results are working, not just installed. On Shopify that means:

  • The web pixel exists with the right site key and is sending events. Cart, checkout and purchase events come from it.
  • The app embed is switched on in the live theme. A theme published last week may not have it.
  • Webhooks for orders and refunds are arriving, because orders are counted from the order Shopify confirms, not from a page view.
  • The plan is active, so experiments can run.

Do this again after any theme publish. One easy way for tracking to break in November is a new theme going live without the app embed turned on.

Step 2: Do orders match Shopify?

Compare a week of orders in your testing tool against the same week in Shopify. They rarely match exactly, and they shouldn't be expected to. What matters is that you can explain the gap.

Common reasons the numbers differ:

  • Orders that never passed through a tracked visit: point of sale, draft orders, wholesale and other sales channels.
  • Shoppers who declined analytics, where the store measures only with consent.
  • Test orders placed by the team. Benchmyrk leaves them out of results unless "Include test orders" is turned on for a goal; other tools may not.
  • Refunds and cancellations, which some reports subtract and others don't.
  • Time zones, when the store and the report cut days at different hours.

Write down the gap as a share of orders and the reasons you found. A store where 40% of online orders can't be matched has a tracking problem to fix before testing; a store where the gap is small and explained is ready. The help article on why orders don't match Shopify lists what to check.

Step 4: Keep your own team out of the numbers

During BFCM prep, agency and client teams visit the store dozens of times a day. Those visits and test orders shouldn't land in results. Exclude office IP ranges, mark team browsers as internal, and agree that test orders are placed only from those browsers. The help article on excluding internal traffic covers each option.

Step 5: An A/A test on every store that will test

An A/A test runs two identical arms. Nothing differs, so the result should show no difference and a split close to the one you set. It checks the assignment, the counting and the order attribution on the real store.

Read two things:

  1. The split. A sample ratio mismatch (SRM) means the visitors you got per arm differ from the split you set by more than chance allows. It is tested with a chi-square test, and Benchmyrk flags it at p < 0.001. An SRM means something in the setup treats arms differently: redirects, bots, caching, consent settings, internal traffic or a script error in one arm. Don't trust results from a store with an unexplained SRM. The SRM guide has the causes.
  2. The result. It should be inconclusive. A single A/A test can still show a "significant" difference by chance, about 5% of the time at 95% confidence, so read it as a check on the setup, not a pass or fail.
ExampleExample

(illustrative stores, not real data; computed with Benchmyrk's statistics engine)

Split checks on a 50/50 test after 20,000 visitors or so:

Example
Arm AArm Bp-value of the split checkFlagged?
10,0009,9000.478No
10,0009,7000.033No: unusual, but above the p < 0.001 threshold. Watch it.
10,0009,5000.0003Yes: stop and find the cause

An A/A test over 14 days with 8,000 and 8,050 visitors and 200 and 203 orders shows a lift of +0.9% with a 95% interval from −16.8% to +22.3%: inconclusive, as it should be. The wide interval is also a useful lesson for the client: at this traffic, a two-week test can't see small differences.

Step 6: Write it into the client report

For each store, record the date of the audit, each check and its outcome, the order-matching gap and its reasons, the consent settings, and the A/A split and result. Keep it with the client's test records. When someone asks in December why a result can be trusted, this is the page you show them.

Mistakes to avoid

  • Auditing once. A theme publish or a new consent banner can break tracking overnight. Re-check on freeze day.
  • Expecting a perfect order match. Explain the gap instead.
  • Skipping the A/A test because "the tool is installed". Installation isn't the same as counting correctly.
  • Treating a small SRM as a warning to ignore. A mismatch at p < 0.001 means the result can't be trusted, whatever the lift says.
  • Letting the team's test orders into results. Mark browsers as internal before the prep weeks begin.

Checklist per store

  • [ ] Web pixel, app embed, webhooks and plan all working
  • [ ] A week of orders compared with Shopify; gap and reasons written down
  • [ ] Consent regions, banner tool and settings recorded
  • [ ] Office IPs and team browsers excluded
  • [ ] A/A test run; split checked; result inconclusive
  • [ ] Audit written into the client's records with the date
  • [ ] Health re-checked on the morning of November 16

Auditing one brand's store rather than a portfolio? Part 2 of the brand track covers the same ground for a single store; start from the BFCM hub. The general timeline is in the guide to testing before Black Friday.

Sources

  1. Fabijan, Gupchup, Gupta, Omhover, Qin, Vermeer and Dmitriev, Diagnosing Sample Ratio Mismatch in Online Controlled Experiments, KDD 2019, read 11 October 2026
  2. Shopify developer documentation, Customer Privacy API, read 11 October 2026
  3. Kohavi, Tang and Xu, Trustworthy Online Controlled Experiments, Cambridge University Press, 2020, read 11 October 2026

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