#BlinkTank: Shopify's checkout deadline arrives next week
We're coming towards the end of August, which means the end of summer, and Q4 is not far off. It's come round quickly this year, as it always does. Right now it feels like the calm before the storm, and I hope everyone's Q4 planning is going well.
The big thing this week - Shopify's checkout extensibility migration takes effect for every non-Plus store on 26 August, and anything running on checkout.liquid or Additional Scripts gets removed rather than carried over.
After that: Anthropic's move to start watermarking AI-generated text, which has reopened the wider debate about AI content, a new 2% surcharge Meta has added to UK Facebook and Instagram ad invoices, a Search Console reporting bug that had a lot of SEOs (us included) briefly worried about AI visibility, some of our own research on search demand, and a Shopify API change that has caught Matrixify off guard on collection imports and exports.
On to the news!
Shopify's checkout extensibility deadline arrives next week for non-Plus stores
On 26 August, Shopify will auto-upgrade every store still on a non-Plus plan to the new checkout extensibility foundation, retiring checkout.liquid, Additional Scripts and Shopify Scripts in the process. Plus stores went through the same (somewhat painful) migration back in August 2025.
The key point is that anything pasted into the Additional Scripts field on the Thank you or Order status pages, including tracking pixels, GTM containers and affiliate scripts, will not carry over automatically. This means any custom functionality will break.
Tracking is one of the more frustrating parts of running an ecommerce store, and this is a good example of why - it is fragile, and it is not something you set up once and leave alone. It needs ongoing maintenance and, more than anything, an owner. We saw that first-hand during the Plus migration in 2025, when tracking broke across a number of stores and working out why took real digging.
Ownership of tracking is one of the bigger levers an ecommerce business can pull, though it is one we rarely see used well. On our own projects we take it on directly where that makes sense, or bring in partners who specialise in it.
Anyone with complicated custom tracking on these pages should ideally have this sorted by now, given Plus stores went through the same change a year ago. If not, there is a limited window left before 26 August, and it is worth keeping an eye on anything that looks off in your tracking data over the following weeks too.
π Upgrading and replacing your Thank you and Order status pages (Shopify Help Center)β
Anthropic starts watermarking AI-generated text
Anthropic has begun adding an invisible watermark to text generated by Claude, with a global rollout under way. The company describes it as a signal embedded in the output itself, and says a full manual rewrite can remove it while light editing probably will not. A detection API is coming but is not available yet.
This has resurfaced a wider argument about AI-generated content. Our position is straightforward: good content can be produced with AI, and the tool used to write it is not the interesting part. What matters is the mechanics: positioning, uniqueness, and whether a page says something no other page says in quite the same way.
Google's public stance, that AI content is judged on quality rather than on how it was produced, is the right one. We are already seeing this in practice: FAQ content on collection pages that is obviously generated with AI and offers little value now looks to be a negative ranking factor.
What watermarking changes is traceability, not quality, and once a detection API exists it becomes possible to know that a piece of text came from a model without that telling you anything about whether it is any good.
That is worth remembering next time the conversation turns to whether content is "AI" or not: the more useful question is whether it's any good.
π Watermarking text generated by Claude (Anthropic)β
Meta adds a 2% surcharge to UK Facebook and Instagram ad spend
Since 1 July, Meta has been applying a 2% surcharge to Facebook and Instagram ad invoices for campaigns delivered in the UK, billed as a separate line item rather than included in the media cost. Meta frames it as a Digital Services Tax surcharge, passing on the cost of the UK's tax on large digital platforms rather than absorbing it.
The mechanics are straightforward: it sits on top of existing spend rather than replacing any of it, so budgets set before July are running slightly over without anyone having changed a setting. The effect on any single account is small, but small percentage costs compound across a large media spend, and it is the kind of thing that is easy to miss in a monthly reconcile until CPA and ROAS both drift a little in the wrong direction.
It is worth checking your own invoices if nobody has already confirmed this is accounted for, particularly if August budgets were set before the surcharge started appearing on statements.
π About the UK Digital Services Tax surcharge (Meta Business Help Centre)β
Search Console's Generative AI report showed a fake drop, not a real one
From around 13 August, a lot of people started noticing the same thing at once: the Generative AI performance report in Search Console showing weeks of steady growth, then a sudden cliff-edge drop within a couple of days. It spread quickly on LinkedIn, with SEOs comparing notes across completely unrelated accounts and asking whether it was a reporting change, an AI Overviews update, or a real shift in visibility.
We saw the same pattern across our own accounts, which ruled out anything client-specific from the start. Google has since confirmed it was never a visibility issue. Its own Search Console data anomalies page logs it directly: a logging error caused a decrease in impressions on the Generative AI performance report in Search for data starting on 13 August 2026, and Google says this affects data logging only. John Mueller added on Bluesky that the team is working on a fix and plans to add an annotation in Search Console to flag the issue for anyone looking at the report.
For now, this looks like noise in the data rather than any real change. Any report or deck built on that data in the meantime deserves a caveat.
π Google Search Console data anomalies (Google)β
Generic search demand is falling three times faster than specific demand
I posted about this on LinkedIn yesterday, and I'm including it here because it's a subject we've been digging into properly over the past few months - search demand.
One thing we kept noticing across clients was demand for head terms falling while the more specific versions underneath it held up: demand for "coffee tables" down, demand for something like "round oak coffee table" flat or slightly up.
Itβs always good to test assumptions, so we carried out an investigation across 25 UK Shopify stores and around 14,000 non-brand terms. We found that generic demand is contracting roughly three times faster than specific demand.
We are not fully sure we trust our own measurement of this though. Keyword Planner and Search Console both suppress the small-volume queries where fragmentation would show up, so the long tail could be growing without us being able to see it.
Shopify's own Q2 data points the same way, with organic sessions rising at the same time search volume is falling.
Full breakdown and caveats are in the LinkedIn post.
π Sam Wright on generic versus specific search demand (LinkedIn)β
Shopify's new collections model is breaking Matrixify's exports
Shopify's 2026-07 API version replaced the old split between custom and smart collections with a single, more flexible model, where a collection can combine automated conditions, hand-picked products, exclusions and sources from apps all at once.
Our team noticed some issues and traced them back to this: apps still calling an older API version do not get an error when they query a collection built on the new model, they just get nothing back.
That is exactly the pattern several of us saw on Matrixify collection imports and exports over the past few weeks. Matrixify has confirmed it is a bug, though there is no fixed date for a fix yet.
If you manage a large catalogue through Matrixify, it is worth checking which API version your export and import setup is running before assuming a broken sync is your fault. Existing collections keep working either way, since Shopify has made this a non-breaking change at the platform level; it is the tooling built on top of it that needs to catch up.
π New collection model and APIs now available (Shopify developer changelog)β
Looking for work
βJenny Kimmerich is someone I've worked with personally, and I can't recommend her enough. She's a senior digital, data and commerce transformation leader with over 25 years across global agencies and client organisations, including transformation work in beauty, fashion, automotive, energy, retail and financial services. She's open to fractional or advisory work helping founders, CEOs, CMOs and CDOs build and scale through periods of change.
If you are hiring and the role fits someone with large-catalogue Shopify experience, or you are looking and have that background, send me a message.
As ever, thanks for reading. If you found this useful, forwarding it on to someone else who runs or works on a large-catalogue Shopify store helps us more than just about anything.
See you next week.
Sam
Who am I and what does Blink do?
I'm Sam Wright, Managing Director and co-founder of Blink SEO. We're a search marketing agency that works exclusively with large-catalogue Shopify stores - the kind where the challenge isn't just visibility, but helping customers find the right product in the first place.
We specialise in SEO and PPC for merchants managing hundreds or thousands of products. Most of our work starts with taxonomy: how a store is structured and categorised, and what that means for organic performance, paid efficiency, and on-site discovery.
If you found this useful and aren't already subscribed, you can sign up at blinkseo.co.uk/blinktank.
If you run a large-catalogue Shopify store and want to talk about organic or paid performance, reply to this email or find me at blinkseo.co.uk.