Has anyone heard of or used AdvisoryCloud?

I recently stumbled across AdvisoryCloud.com (I forget how). But it's a marketplace where advisors in topics like cybersecurity, can meet with companies seeking advisors/consultants. It looks interesting, but I'm not ready to throw down the monthly fee until I learn more. They claim you can make a pretty decent amount of money (ie: $500 for a 1-hour meeting). In theory, this makes sense as C-level advisory work would easily pay this. However, I'm not sure what your typical (non C-level) cyber advisor could charge. So, has anyone used them and can report on your experience? 

A search for 'cyber security', produces 256 cyber advisors looking for work, so it looks quite competitive:
https://www.advisorycloud.com/use-advisors/browse/search?keyword=cyber%20security

I'm not a director or CISO, however in my current role I know that I've provided guidance and advice that has changed the direction of the program and produced great results. I'm just hoping companies would want to talk with the engineers and not just the big cheese type people with a "C" in their title. I could see this being a great side-income, while helping develop soft-skills and advancing in the career field.