I wrote The Startup Gold Mine (https://amzn.to/2FcaoAR) to show you how to leverage large companies to grow your business. I've built and grown 3 profitable businesses, including a venture-backed company. Along the way, I also helped The Estee Lauder Companies create their External Innovation department.
Can you give me more details on what's required of the companies? How much are the listings? Is there anything special about your audience, etc? All of these factors influence what channel will be most effective