Your product needs people. Why would anybody spend two years, 6 months, or even a couple of weeks of their lives designing and building something nobody uses? It doesn't make sense, yet some of the smartest people in the world do it all the time. We really tend to think, "If you build it, they will come," yet that's never the case. Every product needs a way to break the ice to get other people involved or it won't have legs to stand on for very long. How do you get people on board with their time, creativity, and money?
You sketch with a purpose and you adopt the mentality of sketching as a group. This is fundamental to design in organizations of people getting started. Everybody on a team can do this. Dan Roam is right. It doesn't matter whether you are a black pen, a red pen, or a yellow pen person, you have to contribute directly at this level. You have to talk in pictures. Great product is never the product of a lone genius, but rather the collective wisdom of a motivated team with a shared vision. Sketching is the best way to codify that vision and strengthen your team.
If a sketch happens in a forest and no one is around to see it, does it even matter?
Sketches are social or not at all. They can't hide in your desk, on your notepad or tucked away in some folder on your computer. In that way sketches are exactly like your product, or your vision for your product. What good are they if you don't open them up to other people? How can they change anything for the better if nobody knows about them? How do you expect to do it all on your lonesome?
At the end of the day if you really believe in what you're doing, you know in your heart you can't do it alone. You need other people--people with expertise in areas like marketing, business development and operations that you don't have. Every day you wait to get them engaged you squander your opportunity a little more. Sketches are how you break the ice and go on to build great products capable of providing awesome experiences for people.
Thinking of the Oscars tonight I thought back to Steven Spielberg who talked about his creative process for generating and sharing a vision with his team:
I do stick figures and things. I can do perspective, I can at least put depth into drawings, but I can't draw.