Pros
Nothing at all. No reason. You could get a shelf stacking job for the same pay but it will be much less demanding and less stressful.
Cons
You could work at any other phone shop and earn double the money through commission. O2 has no commission for sales, they pay about 20 pence over minimum wage but they expect us to hit unreasonable targets. They have no respect for customers; customer service is shocking and all I do when working there is apologise on behalf of the company for giant mistakes they made, many of which have resulted in customers losing time and money. The ombudsman should be involved and cut this company down to size. (This is partly due to the merger of Virgin Media and O2).