Pros
True entry level sales, mail, and shipping experience for other shipping or packing work. You also combine the skills of working with customers along with packing and shipping. They offer higher prices for packing, stamps, office supplies, and moving boxes, but that leads to an almost unparalleled convenience in regards to shipping. Seriously, I know that sounds like a company line but if you need to copy a document, send insured mail, send a weirdly shaped item, and buy stamps all at the same time, the UPS store is very convenient if you're willing to pay a little more. Also at Christmas time if you want to just get all your presents wrapped and out as quickly as possible, the UPS store is a good bet. So if you work there, you gain a lot of experience in the way things are shipped and the best and cheapest ways to get it there, and you can parlay this into a better job. Otherwise, all these conveniences mean that you, as the worker, get all the hassle of a post office, a copy shop, and just a retail store along with having to ship some poor dudes antique baby crib to Alaska for 400 bucks.
Cons
The pay is not the best. Also, you feel as if you're competing with UPS itself with higher prices. UPS wants customers to have accounts with them, and these accounts would bypass money going to the UPS Store, which is just a franchise. Also, the UPS Store represents the actions of a much bigger company, like UPS and the US postal service. If these companies screw up a delivery, you as the sales associate receive the full brunt of the customer's dissatisfaction, when you might have done a fine job yourself. And since UPS and the post office are less accessible than some poor slob at the UPS Store, that slob tends to be blamed more readily than a faceless organization, considering the fact that we as sales associates often have to argue with UPS and the post office too.