I joined Ning and looked up Cooking networks. I found many networks but each network had only one or two members (not what I see as a network). In Ning each member can set up their own network so the result is many "networks" with a few members. Some "networks" were by invitation only (how do they expect to form a network if interested people cannot access the site).
This seems an inefficient method of trying to make contact with people who have similar interests to you. There should be only 1 or 2 networks with many members rather than 20 networks with 1 or 2 members.
These small networks could benefit by facilitation. An online Facilitator could explain the benefits of combining networks and offer to help set up one network which members of all these smaller networks could join & as a result communicate with people who have an interest in cooking.