The constant change of a Social Strategy

Would you ever buy something before you knew it worked?

This is what I think of when I am making a social strategy. There are some that believe once you have a strategy in place, it does not change, you steer the ship and at the end make changes. I believe this is wrong, when it comes to Social Media things change at such a high pace that if you're not at least trying new things outside of your strategy and make changes along the way, then you're going to lose more than you win.