Ah - well you're directly tapped into the problems they all have, even if they see you as just a tool. You're working with so many different businesses that you have a bigger sample size. What's a recurring problem? How can you solve it at scale? Not saying it's easy at all, but you probably have an advantage over someone who just works for a single company.
We just started by solving our own problems as a marketing agency. Eventually we found one that enough other people had (through this testing process).
Point is, the people I work for see me as a tool. They pay me money for my time to solve the problems they identified themselves.