The Final Days
While listening to the Dan Drake episode of NerdTV, they mentioned John Walker's infamous Information Letter 14, aka "The Final Days".
Autodesk at the time was riding high on the success of AutoCAD, but John Walker, one of the founders, looked on in pain at what he saw. He saw a market leader so entrenched that they were coasting, and were a tempting target for any company with a desire to turn precision drafting into a common tool for the masses.
With hindsight, we know how things turned out. But "The Final Days" is still an incredible read, an excruciating bit of writing that shows how Walker saw the danger of failing to cannibalize the sales of your own product before a competitor does it for you.