Avantages
Every job after this one has seemed better than it actually was, in comparison. If you actually *want* to work in high-pressure, low-reward, high-turnover sales, you won't find a better place to develop the skills you need.
Inconvénients
Every single person you talk to in an endless string of identical days is either trying to sell you the dream of your success if you just get your numbers up (the management) or trying to get you to break out of the script and acknowledge that they don't want what you are selling (cold-called potential customers). Your treatment is based on your value to the company, so if you make a lot of sales everyone is your friend and the future is bright. But you are only given promising leads - i.e. lukewarm calls, rather than cold calls - if you are already making a lot of sales Statistically it is almost guaranteed that your only contribution to the company will be a rounding error in the average length of employment, which on the sales floor tends to be ~ 2 weeks.