Unfortunately it's not actually "free advertising." Just by going onto the show you give up 5% equity of your business to the producers. Still a great show though and probably worth more than the 5% for most companies.
That was true before but no more.
NONE of the companies have to give up any of their business like this. And the ones who did no longer have to.
Reason is that was part of Marc Cuban's demands for coming back this season.
Think about it if they don't have to give that 5% up to the producers then they have just that much more to give to the sharks.
http://www.inc.com/will-yakowicz/mark-cuban-forces-shark-tank-to-remove-equity-clause.html
A couple of my friends have been on the show.
The biggest success is the guy who had the Scrub Daddy. They did 16 million in sales last year.
**broken link removed**