You should definitely speak. It's marketing. It's like writing a book: you hardly get any money for it, but it's great marketing. However, you should never pay

You should definitely speak. It's marketing. It's like writing a book: you hardly get any money for it, but it's great marketing. However, you should never pay to speak. And you should limit your conference attendance to places where you can speak (don't just go to a conference without speaking there, unless it's really important). Yes, you should speak. Running a business and being profitable isn't just about spending time coding, it's about promoting as well, and speaking at relevant conferences is a great way to do that. One of the best.