In my world, I use this idea in the following context:
- Test internally with engineering (QA)
- Test internally with non-engineering (Marketing, etc)
- Test by releasing to trusted users on our forums
- Test by sending the release to particular people who email into Support, whose problems may be fixed with this release
- Test by releasing to everyone on our forums
- Test by releasing to a small number of people who download through the website
The idea of quality feedback loops for your product will be saved for another blog post. Lets just say that twitter has been proving quite useful in getting product feedback lately.