I've since paused my Adwords campaign because the CPC is too high (going to wait until I set aside time to optimize my quality score to turn it back on) but last year about a third of our closed projects came in from Google Adwords.
Here's a few pictures:
I've found that one of the best ways to be less wrong overtime is to do an analysis of why an idea wasn't successful. It can be overwhelming to try to dig into analysis, but I've found that being wrong usually came from a few different reasons. These five reasons usually relate to business/marketing but can be applied to other ideas you develop or want to execute.
First I'll state the five reasons, then I'll explain a little more my thoughts on how they apply to the real world.
1. There were false assumptions made
2. The idea was a bad fit for you
3. You didn’t understand the psychology of the applied tactic / technique, and thus there was an error made in application