Productyping, the evil twin of pretotyping

In the Pretotype It book, I describe productyping as follows:

Productyping is the evil twin of pretotyping.  If pretotyping can be summarized as: “make sure you are building the right it before you build it right,” productyping can be summarized as: “build it right even if you are not sure you are building the right it.”

Here are some signs that you might be productyping instead of pretotyping:

• You add non-critical features and embellishments that no user has requested.
• You worry about scalability when you don't even have 100 (or 10) users.
• You spend too much time to tweaking the UI: This line should be 3 pixels instead of 2.
• ...

And here's the grandaddy of them all:

• You prematurely design and develop a general solution instead of addressing specific needs, problems and requests of your existing users in a timely manner.

This XKCD comic really hits the spot on this last point:

Alberto