C2 offers two ways for a system developer to "experience" his or her own system. You can outright "subscribe" to your own system -- just like a reguar subscriber. In this case, everything will be exactly the same as if you were a real subscriber. You will be charged your own subscription fee, will receive all billing-related emails, etc. This option allows system developers who want to see exactly what a customer experiences to have that customer experience.
But you do not need to subscribe to a system in order to enjoy subscriber-like functionality. System developers automatically will receive signal and broadcast emails from their own system and will be able to AutoTrade their system -- all without overtly subscribing to it. It's up to you which option you want to use.
AutoTrading your own system in real, live brokerage account has its benefits. See related article: TOS Program.