User personalization involves delivering content and functionality tailored to individual user needs without requiring effort from the user. In eCommerce, this personalization is achieved through dynamic content based on customer data like demographics, browsing history, and device usage. Implementing user personalization is crucial for reducing bounce rates, improving conversion rates, and increasing sales. Techniques such as remembering light/dark mode preferences, using geolocation for content suggestions, and storing shopping cart items help enhance user experience. Fingerprint Pro provides a unique visitor identifier to facilitate personalization even in incognito mode, offering solutions like persistent shopping carts and personalized search history. It emphasizes the importance of validating client-side data and suggests steps for configuring personalization use cases with their JavaScript agent, promoting a seamless and tailored user experience.