Pros
Nice discounts on gear; Fun to work with coworkers. They have tons of gear to offer. You have the opportunity of trying it for yourself and seeing if that is something that you want to own. You also get to expand your knowledge of technical specs of instruments and gear, learning what's important to you and what's important to the customer's need of the gear you sell to them.
Cons
Possibility of being overworked for so little pay. You have to do everything, and I mean EVERYTHING! From keeping your space clean to cleaning the entire floor. God forbid, you're the only one on the floor in your department and a host of impatient customers come flooding in all at once. It can be difficult to get help from other coworkers because of how understaffed business days can be. If you're scheduled to close, you can expect to be in there for at least another hour or so. Almost impossible to make commission; Favoritism.