Vantaggi
Flexible enough time that I was able to work two other jobs with it (one full time, the other part-time), good hourly compensation since the company is based out of California and usually has well-known, established clients seeking third party contractors.
Thoroughness of training from clients varies, but the regional managers I had were always willing to help and would promptly return calls whenever there was an issue or question, but it helps to be proactive and educate yourself with the literature provided. The nature of the job depends on which client you're working on behalf of, but there is typically is a lot of brand education and promotion, with some technical troubleshooting thrown in for existing customers of a company's product, all to boost sales.
We weren't pushed to sell, but that's the end goal. However, it was very useful to let people know that I was there for product education purposes and that my pay did not depend on sales, because it increased their trust and usually did result in an actual sale.
Svantaggi
There wasn't enough steady work after the first contract. CCS got our hopes up, saying the client would extend the length of program after the first two phases ended because they were so pleased with the results. However, this did not happen and it kind of disrupted my plans to do this while going back to school. Neither did they have consistent local opportunities for almost another year.
Despite this, I think things are picking up as they seem to have new jobs available locally, so I would definitely recommend CCS to those seeking a lot of flexibility (students or those who just want a little extra income).