MurmTools — WritingResearch and teardowns. Every piece rests on something we measured.https://murmtools.com/writing2026-09-02T00:00:00ZMurmToolsWhat a store's third-party stack tells youhttps://murmtools.com/third-party-stack2026-09-02T00:00:00ZWe maintain fingerprints for 317 third-party domains across 243 companies. A third exist to identify visitors. What a competitor's stack reveals.How accurate are Shopify sales estimates?https://murmtools.com/sales-estimates2026-09-02T00:00:00ZNo storefront publishes its sales. Every revenue figure you have seen from a spy tool is inferred — and the category puts its own accuracy at 70 to 85 percent.The update that disables itselfhttps://murmtools.com/extension-permissions2026-09-02T00:00:00ZAdding a permission disables an extension until every user re-approves. One developer lost ~2,000 users in a day. What the warning means, and which words matter.Affiliate disclosure: where it has to behttps://murmtools.com/affiliate-disclosure2026-09-02T00:00:00ZA disclosure in the footer of a 4,000-word review is not a disclosure. Placement is the requirement — before the link, where a reader will actually see it.Break-even CPA: the number to compute firsthttps://murmtools.com/break-even-cpa2026-09-02T00:00:00ZMargin says whether a product is viable. Break-even CPA says whether you can afford to advertise it — worked from a real landed-cost model, including the 3x rule.Rate beats the point estimatehttps://murmtools.com/velocity-not-estimates2026-09-02T00:00:00ZEvery research tool gives you a number. None gives you the derivative. Why the direction of a figure is more useful than the figure, and why nobody sells it.Blocking AI crawlers: what robots.txt can dohttps://murmtools.com/block-ai-crawlers2026-09-02T00:00:00Zrobots.txt is a request, not a fence. Which AI crawlers honour it, why silence means permission, and the one rule most sites get backwards.Product schema: declared vs shownhttps://murmtools.com/product-schema2026-09-02T00:00:00ZRich results come from structured data, not from what a shopper sees. The two drift apart constantly — and the machine layer is the one Google reads.The de minimis cliffhttps://murmtools.com/de-minimis-dropshipping2026-08-24T00:00:00ZConsignments under €150 into the EU clear without customs duty. Cross it and duty hits every unit at once — 40 units landed 9.6% dearer each than 35.The Consent Gap Index 2026https://murmtools.com/consent-gap2026-08-05T00:00:00ZWe measured 5,294 websites. 96% of those with a consent banner contacted third parties before you could answer it. Method, caveats and raw data included.Shopify spy extensions comparedhttps://murmtools.com/compare2026-07-23T00:00:00ZShopify research extensions compared: MurmSpy, Koala Inspector, PPSPY and others — permissions, package size, and measured data versus estimates.Meta Ad Library tools comparedhttps://murmtools.com/ad-library-tools2026-07-23T00:00:00ZMeta Ad Library extensions compared: permissions, what each can actually read, and why replaying Facebook's private API risks your own account.We took apart 40 Shopify spy extensionshttps://murmtools.com/teardown2026-07-20T00:00:00ZWe unpacked 40 Shopify research extensions and read the code. What that all-sites access is used for, and how to check any extension yourself.