Pay is a little on the low side for this sort of work and you don't receive a commission despite pouring your soul into making a close because ultimately, when the customer is satisfied with your sales pitch and wants to buy, you can't sell it to him directly, but you gotta refer him to an authorized reseller because Canon does not do direct sales. That can be a bad point for those who want to get into it for the commissions and thrill of the sale, but I sometimes find it liberating because you don't operate under a quota that way so you can just be honest and ethical in your practice with the customer, and try to truly serve the customer's interest like a good customer service assistant rather than to be an unscrupulous salesman.
Work can be a little menial and tough, especially when you are helping out with gift redemptions (post-PC shows) and the like and that reduces the time you otherwise have to stand around and look glam, or to discuss photography and cameras with some customer which is a little more stimulating. Also, as with a customer service job, you can expect from time to time the nasty, complaining customer who cannot be placated easily - mostly, you can refer this to the senior perm staff though, and you can just stand back and watch and learn, so you learn a bit about people skills this way too actually, as long as you can take the initial heat of the grumpy customer.
There's a degree of politics you can witness that occurs at the higher levels, but part-timers and temps are insulated from that; you hear it more from the perm staff talking among themselves about others in other departments and in higher chains of management. If you're really affected by these things then perhaps your work satisfaction might be impacted a little, but for the most part again, this doesn't concern the part-timer but... Just be watchful about mood changes among the perm staff who are affected by the winds of change and political intrigue, and don't be triggering them off at the wrong time.