Another way of looking at it: Nothing is ever 100% done when it launches. Nor should you wait for it to be, if it's been tested to your own complete satisfaction. I frequently launch things over 3-4 different beta phases to increasingly large swaths of customers, while documentation is still being hashed out by staff who are coming up to speed on the feature themselves. My goal is that at the 1-year mark, more or less, there are almost no bugs, by which time I've forgotten the nuts and bolts of the code. Meanwhile there are other features and pieces of software that need building.
