The entrepreneur's dilemma: Justifying contributor agreements in open source

At the start of the summer, you may recall Project Harmony causing a certain amount of controversy on the subject of contributor agreements in open source communities. My position on them was and is that they are a rarely needed and exceptional tool that should be avoided unless essential, because of their negative effects on the dynamics of open source communities.

One prominent commentator asserted during that discussion that a software company that wants to promote open source has to use contributor agreements if it wants to make money. While that sounds superficially reasonable, I contend that actually that statement is a circular argument. If you've chosen to build your business around a model that requires the accumulation of copyright, then you will need a contributor agreement to make that happen....