When learning about the product you're testing, sometimes it can be helpful to read support and developer forums. This of course assuming your product has those forums. If not, call center logs and FAQs can also do the trick. A lot of people only use information like this to see what doesn't work or where the product might have issues. And it's good for that. But you can also learn:
You can learn a lot in forums, not only about the product, but about the culture of it's users.
- Where have people become subject matter experts?
- Where is there a lot of energy for the product? (Think of this in terms of traffic for a particular forum or topic.)
- What new features (as opposed to bugs) do people ask for?
- What are people doing that's not done the way the designers expected?
- What other products are often mentioned in association with this product?
- etc...
You can learn a lot in forums, not only about the product, but about the culture of it's users.