Ever downloaded a podcast, thought hey that's good, think I'll subscribe? Every couple of weeks or so a new podcast is released and you enjoy the listening. It might not even be a podcast, could be a good cause, a blog article or even an opensource application your using.
The above could be classed as products. Products take time, effort and dedication. Think of all the blogs out there running on wordpress. Out of all these blogs at what percent do you think they have donated back to wordpress? A guess would be that it's a very low percentage....