The Broadsheet

Published by Spambuster
Edition N°01 · 26 July 2026
Reporting on Shopify form spam, by the people who build the filter Three dispatches
Dispatch N°01 · Investigation

The CAPTCHA on your Shopify store costs $1.50 per thousand to defeat

Merchants who enable Shopify's spam protection and keep receiving spam are usually told they configured something wrong. They did not. Solving services publish their rates, and defeating the challenge on a contact form costs the sender about a tenth of a cent. A coverage map, the four routes around the gate, a ten-minute triage, and a matrix of what every defence actually stops, ours included.

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Contact form hCaptcha Solving market 15 min
· Spambuster ·N°01
ROUTESDiagnostics
Dispatch N°02 · Investigation

Your signup form is being used to bury credit card fraud

A Signifyd employee woke one Sunday to several hundred unread emails. Buried among them was a $1,300 Apple Store receipt she had not authorised. Every one of those messages came from a signup form on somebody's website. Researchers who analysed 24 such campaigns found the traffic almost impossible to filter, because it is genuine mail sent by real shops that did nothing wrong except leave a form open.

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Subscription bombing Deliverability 15 min
Dispatch N°03 · Field guide

What a reCAPTCHA score actually means — and where to set your threshold

A spam filter's dial has nine positions, of which roughly four produce distinct results, and one blocks every submission the store will ever receive. What the number underneath represents, why a new store's scores cannot be trusted, and what is traded away at each end. With a sorting rack you can drag, our behavioural signal weights published in full, and the one question to put to any vendor ahead of the pricing question.

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Interactive Thresholds Honeypots 14 min

How these are reported

Four rules, because this category has a credibility problem

Primary sourcesPlatform claims link to Shopify's, Google's or Klaviyo's own documentation. Prices link to the vendor's published price list. Research links to the paper.
Models are labelled as modelsWhere we estimate, the assumptions are printed alongside, along with the point at which the conclusion would break.
We record where we don't helpNo filter stops a human typing a sales pitch. That appears in the same table that recommends our own product.
CorrectionsIf something here is wrong, tell us and we will change it and say what changed. contact@jola.com.au

Return spam to sender.

Invisible Google reCAPTCHA scoring on every Shopify storefront form — contact, newsletter, comments, reviews, login, registration and checkout. Two minutes to set up, no keys to paste.

Install on Shopify — free for 14 days →
No credit card to try·From $3/mo·Cancel anytime