Google Shopping shows products with image, price, and store name directly in search results. Click-through rate is higher than regular text ads, and since 2020 there's also a free listing option. WooCommerce can be connected relatively easily.
Google Merchant Center
Create an account at merchants.google.com. Verify and claim your domain. This is the hub: your product feed goes here, from here products are distributed to Google Shopping, free listings, and Shopping ads.
Product feed
CTX Feed (free) or Google Product Feed plugin for WooCommerce. Generates an XML feed that Merchant Center fetches. The feed contains title, description, price, image URL, stock status, GTIN (barcode), brand, and product category.
Feed quality determines whether products are approved. Google rejects products with missing required fields, image errors (too small, watermarked, text on image), or price not matching the website.
Titles and descriptions
The product title in the feed should contain brand, product name, key attributes (color, size). "Nike Air Max 270 men black size 43" ranks better than "Nike shoe". Google matches the search term against the product title. Be specific.
Free vs paid listings
Free listings appear in the Shopping tab and sometimes in main results. Paid Shopping ads (via Google Ads) appear at the top. Most stores start with free listing and add paid when they see results.
Common rejections
Price mismatch (VAT included in feed but excluded on site). Missing GTIN for branded products. Images with overlay text. Fix them in Merchant Center under "Diagnostics".