Within the twelve month period you can see how sales are and if it is economical to defend the patent as well as keep an eye out to see if the other company is developing a copy. If that is the case and economical to defend the patent then all the copying and production of parts could be a loss for the other company for up to 7 years. On the other hand if it is not economical then you are only out the $125 provisional filing fee and you continue to sell in the market with the copies now available.