What method should be used to personalize emails for subscribers based on data stored in a reference data extension?

To personalize emails for subscribers using data from a reference data extension, using AMPscript with the LookupOrderedRows function is the most effective approach. This function allows you to retrieve multiple rows of data from a data extension based on specific criteria, enabling you to pull relevant subscriber information directly into your email content.

In the context of email personalization, AMPscript allows for dynamic content generation that can adapt based on the recipient's attributes stored within the data extension. The LookupOrderedRows function not only fetches the data but also maintains the order of the results based on specified fields, making it particularly useful when the order of the data is important for the email's context—such as displaying a list of products or services tailored to the subscriber’s previous interactions or preferences.

This method is particularly advantageous as it minimizes the complexity often associated with code while maximizing the flexibility of content personalization. By efficiently utilizing the stored information, you can create a more engaging and relevant experience for the recipient, directly enhancing the effectiveness of your email campaigns.