A useful new-to-brand review combines acquisition share, acquisition cost and contribution; it does not rank campaigns by NTB percentage alone. Start by checking which NTB fields your export actually provides and whether the compared campaigns use the same attribution basis.

For the definition of NTB sales and its 12-month purchase-history lookback, see the NTB metrics explainer. This article focuses on assembling a repeatable measurement review.

Build one consistent reporting table

Record the account, marketplace, campaign type, currency, reporting period, export time and click/view scope. Keep spend, total attributed sales, total purchases, NTB sales and NTB purchases together. Do not merge columns from different reports merely because the labels sound similar.

Amazon documents NTB reporting for supported advertising products and defines it with a purchase-history lookback. Availability depends on the selected report. A missing field is not a reported zero. Amazon NTB guidance.

Calculate four complementary measures

Measure	Formula	Limitation
NTB sales share	NTB sales / matching total sales	Revenue share, not customer count
NTB purchase share	NTB purchases / matching total purchases	Purchase share, not unique people
Cost per NTB purchase	Campaign spend / NTB purchases	Allocates all campaign spend to those purchases
Contribution after advertising	Contribution before ads minus spend	Requires a consistent economic basis

When a denominator is zero, show the ratio as unavailable. If the source failed, show missing data. Preserve those states separately in the dashboard.

Compare acquisition campaigns with similar objectives

Hypothetical example: two campaigns each spend £300 and report £1,000 total attributed sales. A reports £700 NTB sales and 14 NTB purchases; B reports £400 and 10.

• A has 70% NTB sales share and £21.43 cost per NTB purchase.
• B has 40% NTB sales share and £30 cost per NTB purchase.
• Both have 30% ACoS because their total spend and attributed sales match.

That does not establish that A is the better investment. Product margins may differ, and a branded retention campaign may intentionally reach existing buyers. If each generated only £250 contribution before ads, each would leave a £50 shortfall after advertising on this simplified basis.

Avoid double counting and false incrementality

NTB sales are a subset of their matching attributed sales total. Do not add them to ad sales or total business sales. Similarly, do not add click-only sales to a combined click-and-view total. Check the metric definitions in Amazon's conversion guidance.

A campaign may receive credit for a purchase that would have happened anyway. NTB classification does not establish incremental acquisition. For a stronger causal question, design a controlled comparison that addresses seasonality, price, product mix and other advertising; ordinary before-and-after reporting remains observational.

Run the weekly review

1. Confirm that exports succeeded and flag periods still awaiting conversions.
2. Compare like-for-like campaign groups and inspect absolute NTB sales and purchases as well as percentages.
3. Check margin, inventory and total business sales before proposing more budget.
4. Record the change, its expected effect and the date for a mature review.
5. Keep the original and refreshed exports so later attribution changes are visible.

Can NTB purchases be called new customers?

Use the precise field name. Purchase counts are not necessarily deduplicated unique customers, and the brand-history boundary is not first-ever purchase across every channel.

What if the percentage rises while sales fall?

Inspect both numerator and denominator. A shrinking repeat-purchase component can lift the share without adding NTB revenue. The dashboard guide shows how to keep these definitions visible.

Related Arctavia resources

Use these supporting pages to compare Amazon PPC operating models and implementation choices.

• Amazon Ad Rejections: Check Claims, Images and Destinations
• Amazon Ads ACoS Suddenly Increased: What to Check First
• Amazon Ads ML Bid Review: Guardrails Before Aggression
• Amazon PPC Automation: Data, Decisions and Operating Controls
• Amazon PPC Automation Migration Checklist
• Amazon PPC Automation vs Agency: Which Operating Model Fits Better?