Hi Eric,
I just started reading your "Lean Startup" book and as I understand the main thing is to validate the idea and build out MVP before building out features that people might not even need.
I am a software engineer and have an idea of building a marketplace to connect brands to instagram users that have a large amount of followers. Sort of like AirBNB for for instagram which can expand into other social media as well. How would you validate this idea "Lean start up" style before coding it. How would you get users and brands on board?