The best site in my opinion is Product Hunt. I look for new start ups here everyday. Also if you want to innovate a good strategy (if you already have a monetizable product) is to do an affiliate campaign where you should: -Define buyer persona -Find the affiliate leads -Analyze which keywords are the more high intend -Extract the leads of this blogs/web pages -Launch an email campaign via GMASS -Create the landing pages where you want the affiliates to redirect their traffic

If you are interested in this channel or any new growth channel, respond to it and I would gladly help you