Forrester analysts Charlene Li and Josh Bernoff have published a report, "Social Technographics," ($279) that identifies six levels of participation in the realm of social media or the social Web in the U.S. based on a recent survey.
The results are not surprising, but looking at target markets from a "social technographic" perspective can be useful. For marketers, the report recommends, the idea is to select the target audience, see where they fit on the ladder and then establish a relationship based on what they are ready for. I suppose you could also try to come up with ways to move a target audience climb up the social media ladder with various schemes, such as better tools and incentives, to turn them into unintended marketers or evangelists (or critics) for a product or service.
The report gives an example of how Apple and Dell computers users stratify on the ladder. As you would expect, Apple users are more in the creator, critic and collector categories and Dell has more inactives and spectators. No surprise: Apple users drink more from the Web 2.0 fountain than Dell users, which is expected given the profile of Mac users and the much bigger market share that Dell maintains.