Which of the following is a benefit of using priority mail?

Using priority mail provides significant benefits, and one of the most notable is the availability of online tracking and delivery updates. This feature allows customers to monitor the status of their shipment in real-time, providing peace of mind and the ability to plan for the package's arrival. Customers appreciate the transparency and reassurance that tracking offers, which can enhance their overall shipping experience.

Other options do not accurately represent the benefits of priority mail. For example, the concept of free packages isn't applicable, as costs are typically associated with mailing services. Local delivery is not a defining feature of priority mail, as it is designed for both local and nationwide shipping. Limitless weight is also inaccurate, as there are specific weight limits associated with priority mail services.