Which of the following is a legitimate use of cookies in e-commerce analytics?

• A. To monitor server performance.
• B. To send marketing emails automatically.
• C. To save user preferences and monitor how visitors interact with sites.
• D. To replace cookies with a different tracking method.

Answer: (C)

Cookies are small data files stored in a user’s browser that help a site remember who the user is and how they’ve interacted with the site. In e-commerce analytics, their legitimate use is to save user preferences—like language, currency, or items saved for later—and to monitor how visitors move through the site. This includes what pages they visit, how long they stay, which buttons they click, and whether they complete a purchase. Collecting this interaction data helps analyze user journeys, optimize navigation, and improve conversion rates.

Other options don’t fit as legitimate uses of cookies. Monitoring server performance relies on server-side logs and metrics rather than client-side cookies. Automatically sending marketing emails is an email-system function that requires consent and separate tooling, not cookie-based tracking. Replacing cookies with a different tracking method isn’t a use of cookies itself but a methodological choice, whereas cookies’ role is to persist user state and track interactions.