Jeff Gothelf addresses a very common problem in his post on the perils of fixed time, fixed scope projects. This point on what it means when you “launch” a product is so important:

Deadlines imply that if we don’t get the product right on the day we launch, we’re doomed. This is an antiquated point of view. Launching publicly simply begins the process of learning how right (or wrong) our assumptions were. It is the start of a continuous conversation with your target audience and the fastest way to learn how to optimise your system. The sooner you can get something to market, the sooner you can make the system better. By the time you get to your deadline, your product should have been in market for multiple cycles.