Group 1:  The method has to be valuable to have people come back.  There must be value to members, such as free telepresence.

Group 2:  Build on your core community of interest - CDMN must define what they do more clearly so stakeholders can attach themselves to what CDMN can do for stakeholders.  In fact, define what is digital media or products without limiting services that can be of assistance.  Everything but tailor it to target community, i.e. social networks for young demographic.

Group 3:  Keep it current and fresh, run content development contests, promote success stories, hold annual networking events, live chat, forums, phone directory.

Group 4:  As the network grows, build peer to peer groups.  Promote success stories, mentors and coaches.  Forum for real collaboration tools.  Best practices.  Knowledge sharing.  Search capabilities and knowledge-base tools.

Group 5:  There must be value - funding, sales, contacts, knowledge.

Group 6:  Email, face to face meetings, social media plus web, newsletters, videos, word of mouth.

Group 7:  Contacts, info exchange focused on the subsets with DM. 

Giving away relevant things for free or little cost is always an effective way to get people to come back for more.  The idea is to find valuable things at no cost and offer as prizes or giveaways (digital items could be given to all because it cost nothing to reporduce them).  Ex: white paper on business model for a particular niche.

Another could be to find an organization (governemnt or private) to finance micro businesses and have contests to determine the winner(s).  Capital outlay is relatively small and it could be the spark to start a movement of very small businesses that could involve work-at-home parents, students doing business on the internet to finance their education, immigrants who are having problems finding local employment, etc.  Of course, appropriate rules are to be set up to be sure the seed money is used properly.