What Spillmark does
Spillmark is an incrementality measurement and profit analytics tool built for Amazon brands that also sell on Shopify or run Meta (Facebook/Instagram) ads. Instead of trusting last-click attribution, it runs geo holdout tests: Meta ads are paused in some US states and kept live in others, then Amazon orders are compared between the two groups to reveal the real lift.
Core jobs it handles
- Is Facebook Ads to Amazon worth it? — Run a geo holdout test to see the true Amazon lift from Meta spend, with a free dashboard and a 7-day $0 trial.
- Measure Meta ads impact on Amazon sales — Replace last-click guesses with a controlled experiment; Standard plan is $49/mo for one Amazon account.
- Geo holdout testing for Amazon sellers — Pause Meta in selected states, keep it on elsewhere, and compare Amazon orders across regions.
- Amazon PPC incrementality tests for branded keywords — Determine whether bidding on your own brand name adds incremental sales or simply collects credit for orders that would have happened anyway.
- Profit by channel dashboard — See what each channel (Amazon, Shopify, Meta) actually keeps after Amazon fees, product costs, and ad spend in one free view.
- Amazon PPC automation with approval — Agents recommend bid and budget changes, but nothing is applied silently; every move requires your approval.
Who it's for
Amazon sellers and DTC brands running paid social alongside marketplace sales, plus growth marketers and agencies that need defensible, experiment-based proof of ad effectiveness rather than platform-reported attribution.
Method and transparency
Spillmark publishes a dedicated page explaining how lift is calculated, and offers comparison pages against alternatives such as GeoLift and Amazon Attribution. Free tools and guides are available alongside the paid product.
