Many people use “complex” as a synonym for “complicated.” In make a complex startup, Peter Ehrlich doesn’t argue to make things complicated. In fact, he says to make them simple. And complex.
An idea must be complex inside (to the founders), for otherwise it is nothing and weak. It must not be complicated inside, for then the founders do not understand their own creation, and more time must be spent.
An idea must be simply represented on the outside (to the users). In a world rich with information, understanding something complicated is a heavy investment on the part of the user. This can only rise in correspondence with the popular belief of the worthiness of your product.
An idea that is complex on the inside, but complicated on the outside is ahead of it’s time. Users need catch up, so that it becomes more simple and obvious.
Some call this simplexity, the idea that a single button can connect to a complex series of events in order to start a car, run an elevator or buzz an intercom.
Taken from the other direction, I like the idea that to be useful something has to be complex. Otherwise there’s nothing left to make simple. In startup terms, you need to solve a problem. And if your problem is too simple, then it might not really be a problem.