# What is Personalization Engine?

What is Personalization Engine? A system that shows personalized content, products, and offers to each visitor in real time — based on history, behavior…

## How it works in practice

A personalization engine is the site's 'personal salesperson.' Amazon attributes 35% of its revenue to its recommendation engine. In a small store: 'customers who bought X also bought Y' is basic personalization that raises AOV.

## Related metrics

- CDP — the data foundation for personalization
- Product Recommendations — the output of a personalization engine
- First-Party Data — data used for personalization
- AI — advanced personalization is AI-based

## Common misconception

'A personalization engine means complex, expensive AI.' Amazon's is complex. 'Customers who bought X also bought Y' is simple collaborative filtering — available as free Shopify apps. Basic personalization beats no personalization at all.

## How to fix it

Personalization not making a difference? (1) Check data quality — enough purchase history? (2) Check placement — are recommendations below the fold? (3) Check relevance — are you recommending products the customer already bought? (4) A/B test personalized vs. non-personalized.

## Real-world example

Bookstore: added 'customers who bought X also bought' recommendations on product pages and post-purchase emails. AOV rose from $22 to $29 (33%). The recommendation engine cost $20/month. ROI: 50x in the first month.

## Where to start

Personalization order: (1) product recommendations on the product page (Shopify: Frequently Bought Together app), (2) personalized email (Klaviyo Recommendations block), (3) homepage personalization (advanced — after a CDP).

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Category: Customer Experience · From the [Jimmy OS KPI Glossary](https://jimmy-os.com/glossary/kpi.md) · Source page: https://jimmy-os.com/glossary/kpi/personalization-engine