Product Type [product_type] Field for Product Feed

Optional for each product

The product_type attribute allows you to submit your own product categorization.
Unlike the google_product_category attribute, which uses Google’s predefined taxonomy, product_type is fully customizable to match your internal classification system.
Google can use this information for better ad targeting, and you can use it to structure bidding and reporting in Shopping campaigns.

When to use

• Always beneficial for products in Shopping campaigns, even if not required.
• Use to match your own internal merchandising hierarchy.
• Useful for granular control over bidding and reporting in Google Ads.

Format

• Type: String (Unicode; ASCII recommended)
• Limit: 0–750 characters
• Repeated field: Up to 5 times (but only the first value is used for bidding/reporting)

Formatting rules:

• Separate category levels with > and spaces on each side (Home > Women > Dresses).
• Do not use commas inside a single product type value : commas separate multiple product types.

Formatting examples:

Minimum requirements

• Use > to indicate hierarchy with a space before and after the symbol.
• Provide the full breadcrumb path for best results.
• Don’t insert unrelated keywords or promotional text.
• Avoid commas within a single product type value.

Products with improperly formatted values may not be correctly categorized in Shopping ads.

SEO Tip

This will give Google accurate data about your product and help it rank them better. Also, using a detailed and consistent product type taxonomy can improve product grouping in Google Ads, enabling more precise bidding strategies and easier performance analysis. The more specific your hierarchy, the better for campaign segmentation.

Official Source: https://support.google.com/merchants/answer/6324406