The conversion PERCENTAGE might be not as accurate, but the fact that the keyword is working still gives you grounds to try to use it in another way to test it’s viability in other ways. Remember, in a Manual Campaign, you can adjust the keyword bids and even shut it off if it isn’t working after a while. So, it’s just a way to get some data to show that your product does perform well on certain keywords.
The new training (as I mentioned below) is more about how you set the campaigns up, and how they are named, but it will have some simplified understandings about how you find good keywords. The concepts will be very similar in that regard though.
You will estimate your revenue at launch by filling out the Launch Cost Planner. Head to the Launching module to learn more about that. 🙂