Guide
Amazon sales down, Shopify up: is the business shrinking?
Part 1
3 checks from exports you already have, in under an hour
Do this first
- Check 1, the total. Amazon's Sales and Traffic by Date report by week,1 Shopify's Net sales by channel by week,2 and your wholesale invoices. Net on every channel or gross on every channel, never a mix. If the total held while Amazon fell, you have a channel shift, and the fix is different.
- Check 2, the turn. When Amazon falls and Shopify rises in the same week, the cause usually reaches both: ad budget moved, a promotion ran on one channel, a price changed, or an email pointed at your site. Weeks apart, they're probably 2 separate stories.
- Check 3, what changed. A shopper who sees the same product $3 cheaper with a code on your site will buy it there, and Amazon's report shows it only as lost sessions.
- Most advice skips this. On October 5, 2026 we read 17 seller forum threads from 2024 to 2026 about a sales drop, and every answer stayed inside the channel the seller asked about, as does our own Amazon guide.
Part 2
Kestrel Kitchen: Amazon fell 20.8%, the business grew 11.3%
Kestrel Kitchen is a fictional brand we built to show the report, selling board oil and care kits on Amazon, its Shopify store, subscriptions and wholesale. These are the 13 weeks to the end of September 2026, against the same weeks a year earlier.
Check 2 found the turn: the week of 2026-06-07. Rows marked "after 2026-06-07" compare the weeks either side of it, and the others are the 13 weeks against last year:
| Number | Channel | Change | What it says |
|---|---|---|---|
| Sessions | Amazon | -36.0% after 2026-06-07 | Fewer shoppers reached the listings |
| Unit session percentage | Amazon | +129 bps, to 12.41%, over 13 weeks | The ones who arrived bought more often, so the listing didn't break |
| Orders | Shopify | +44.5% after 2026-06-07 | The same week, demand showed up on the site |
| Net revenue | Shopify | +50.9% after 2026-06-07 | Revenue rose a little faster than orders, so order value held up |
| Net revenue | Total business | +11.3% over 13 weeks, to $160,318 | The customers didn't leave |
Part 3
3 causes ruled out, and ad budget left standing
Do this first
- Pull ad spend by channel and month, Amazon Sponsored Products and paid social together.
- Check whether budget moved in the week your channels turned.
- If it moved on purpose, compare margin by channel before you move it back.
- Category downturn, ruled out. All 4 competitors' Amazon rank held steady from January to June 2026 while Kestrel's Board Oil 8oz slipped, so shoppers didn't leave the category.
- Seasonality, ruled out. The same weeks of 2025 moved 2.3% in Amazon sessions and 0.8% in Shopify orders.
- Amazon price, ruled out. Board Oil held at $14.99 throughout, and its premium over competitors didn't change.
- Falling sessions with rising conversion fits losing paid traffic. Ad budget moving to the storefront is the one candidate that reaches both channels in the same week, and it's the first action in Kestrel's sample report. If it moved on purpose, the question is whether the move made money: profit by sales channel works that through on the same brand.
Part 4
When it is Amazon: split traffic from conversion
Do this first
- Confirm the total business fell with Amazon, or Amazon turned in a week nothing else moved.
- Run the Sales Drop Diagnostic on 4 numbers from Business Reports.
- Follow the branch that fell in the Amazon guide.
- The Sales Drop Diagnostic splits the drop into traffic and conversion from 4 numbers in about a minute.
- Why are my Amazon sales down? walks the 5 most common causes, and every field those tools ask for is defined in Amazon Business Reports, explained.
- A monthly review catches it early by adding up every channel before explaining any one. The monthly business review template is that page, and the Growth Loop is the method behind it.
Not sure which one you have?
Tell us where you sell and we'll run the 3 checks across every channel, the way the Kestrel example does, with the causes tested and the actions ranked. The first month is free, and we never log in to your accounts.