Many skills learned on the job that will be valued almost anywhere.
Pros
Rarely boring / Meet many interesting people and learn things through engaging in small talk / Develop better customer service skills and learn to become more personable / Proper packaging techniques and custom packing requires some creativity and basic understanding of math and physical science understanding the effects of shock, compression, weight changes, etc. for a variety of materials and shapes / Understanding how document, print services works / Mail systems and sorting mail / Learn how to deal with insurance claims & shipping policies.
Cons
UPS benefits do not apply to employees of the retail franchise, The UPS Store. There's not a whole lot of room for advancement within the franchise without the intention of owning a franchise one day, yourself (costomer service clerk, manager, owner). Like any customer service job, there are crappy situations with people and disgruntled, sometimes just weird customers. With packaging: People will bring in very awkward or difficult-to-pack items and expect you will be able do easily pack them properly in some unreasonably short amount of time and cost near nothing for the materials. Some people will expect they can toss anything in any box, maybe throw in some crumpled paper or clothing around it, a little tape, and then get mad at UPS if it breaks. So understand how to simply explain the system, and be able to end a discussion respectfully without going on in circles for no reason.