I was recently directed to read an interview with Sun Microsystem's CEO/COO, Jonathan Schwartz regarding his Open Source business strategy. This is particularly relevant given their new MySQL acquisition.
Jon stressed the necessity of driving adoption to generate revenue. He claims that seemingly competing products like Red Hat and Solaris complement each other because both are going for the same goal - look out M$! He makes a distinction between his "community" (users) and "market" (paying customers), insisting that one leads to the other. A casual user or developer shouldn't pay for his software, while that same individual might recommend purchasing it with a hefty support plan for a mission critical operation.
Sounds good to me! Establish a solid brand. Sell "systems" and "the experience" instead of hardware or software (think Apple). Provide an abundance of value without squeezing pennies from your customers - this also acts as free advertising. We'll see to what extent a certain industrial software company with killer products can follow suit.