Structured data, the schema.org product markup embedded in your pages, is how LLMs, shopping agents, and search engines actually see your Shopify store. Your theme is for humans. The colors, the typography, the carefully art-directed hero: machines read none of it. They read the machine-readable layer underneath, and for a growing share of your future customers, that layer is your storefront. When someone asks ChatGPT or Perplexity for “the best insulated water bottle under $40”, the systems answering that question shop your data, not your design.
Back in tip 26 we made the argument that agentic shopping is coming. This tip is the practical half: audit what the machines currently see, because most merchants have never once looked, and what is there was decided by theme developers and app defaults, not by anyone who cares about your revenue.
One product page, two audiences
The right panel is what an agent shops. If a field is missing there, for that audience it is missing everywhere.
“name”: “Summit Bottle 32oz”
“price”: “38.00”
“availability”: “InStock”
“aggregateRating”: missing
“gtin”: missing
Nobody art-directs the right panel, which is exactly why auditing it is an edge right now.
The 20-minute audit
- Run your bestseller’s URL through Google’s Rich Results Test. It shows exactly what structured data your page emits, plus errors and warnings. Most Shopify themes emit basic Product markup out of the box; the question is whether it is complete and correct.
- Check the fields that sell: price, currency, availability, review rating and count, brand, identifiers like GTIN or MPN. “Missing rating” means every review you collected is invisible to this entire audience. “Availability: out of stock” on an in-stock bestseller is a five-alarm bug you would otherwise never notice.
- Test one of each page type, not just one product: a collection page, a variant-heavy product, a sale product (is the sale price the one in the markup?).
- Check your feeds too. Your Google Merchant Center feed is structured data with a different hat on, and agents lean on the same product attributes. Clean titles, real categories, filled attribute fields: the boring plumbing is the marketing now.
Fixing what you find
Gaps usually trace to one of three places: a theme that emits skeleton markup (fix in the theme, or choose a review or SEO app that injects the missing pieces), product data that was never filled in (no markup can emit a GTIN you never entered), or an app conflict double-emitting contradictory markup, which reads as spam to machines. None of these are glamorous fixes. All of them compound: the same clean data feeds Google’s shopping surfaces today and every agent that shops on your customers’ behalf next year. The stores that treat product data as a first-class asset are the ones the machines will be able to recommend.
