Becoming a keynote speaker at events is part of an integral step to grow one's authority. There are many successful business owners who want to expand into the speaking arena but are not able to book speaking gigs. This is because they are not well-positioned as speakers on the internet. Their website does not make them out to be an authority on a specific subject area. This is a big problem.
If people do not see you as a speaker they will not pay you to speak or give you nice accommodations. Instead, they will ask you for thousands of dollars to set up your own booth at their conference. You must create a personal brand so that when people are organizing events, they WANT you. Have a section on your personal website with clips of you speaking at various events as well as testimonials from event planners or people in the audience.
You may also want to have a longer video (around 15 minutes) of raw footage of you speaking at an event. This will help recruiters get an idea of how you are as a speaker. This will be what convinces them to sell you to their superiors.
If you are new to the speaking arena, start working for free. Try to book as many events as possible and build experience. You might be able to book another event if you are able to impress the current company. The more you speak, the more you build your authority on the subject.
If you want to try speaking to your customers, do not worry about the numbers. Speaking to thirty people who in your target audience is much better than addressing five hundred people who want nothing to do with you. Take the opportunity that speaking provides for you and collect new leads. Work with the even planner to get information out to the audience before they even come to hear you speak. This will get them more connected to you before you even enter the stage.