I guess my greatest strength (as clients have told me!) is the ability to listen and immerse myself in their world from the off. I don't believe there are any stupid questions and I will ask and ask until I know who you are, what you are, and who your audience are.
The answers to these questions often replaces the 'what you want' with the 'what you need'.
Whoever the client, whatever the product or service and whoever the audience, everything needs to say something to someone, and I never lose sight of that.