I am an Entrepreneur, Marketer and a Growth Hacker. I help organisations and startups acquire customers and accelerate growth. I have founded 3 ventures in Internet and Mobile space.
Free/ Freemium / Charged is a decision based on a number of factors including the domain (product), competition landscape, scale and speed of growth.Could answer better if you share details.
You could start with LinkedIn (Profiles and Groups). Search for Marketing Executives and join the relevant groups. For example, this group http://linkd.in/1a8zR3c