Why add-to-cart rate matters
Sitewide conversion mixes two different problems together. Splitting out add-to-cart shows whether the leak is product-page conviction or checkout friction, which need different fixes.
Reading add-to-cart rate
- High add-to-cart, low checkout completion: fix checkout
- Low add-to-cart on healthy traffic: fix the product page
- Compare by traffic source, not just sitewide
- Watch it after price, photo, or review changes
Questions
What moves add-to-cart rate?
The things shoppers check before committing: photos, price clarity, visible reviews, shipping and return answers, and how fast the page loads.
Is session-based or pageview-based better?
Either works if you stay consistent. Session-based reads cleaner for the funnel; per-product-view helps compare individual products.