If you’ve ever talked to Forrester about social media, chances are you’ve heard of the Social Technographics® Ladder — our tool for measuring how people use social technologies and for helping marketers (and product strategists and market researchers and others) understand how to engage with those people in the social Web.

Today we’ve released our new 2010 Social Technographics data worldwide (you can see the US data here), and you’ll notice that this year, for the first time since we introduced the ladder, we’ve added a new category of social engagement. The new category — “Conversationalists” — is designed to capture the short, rapid conversations that are now taking place on Twitter and through Facebook status updates. How many people are engaged in these behaviors? Almost one-third of European online adults participate in these rapid public conversations every week. In just over two years, this activity has come from nowhere to become one of the most popular social behaviors we track.

And this Conversationalist activity has come along at just the right time, too — because more “traditional” forms of online contribution have levelled off. The percentage of online Europeans who post their own blogs, videos, photos, or other media — what we call “Creators” — hasn’t grown in either of the past two years. And the percentage who participate in message boards and forums or who post comments on blogs or other social sites — what we call “Critics” — has grown just one percentage point in Europe each of the past two years.

What does this mean for marketers? It means we need to stop and re-evaluate how our audiences are using social media to find the new opportunities that fit best. It means that rather than simply watching all social media behaviors grow as we used to, we need to understand that some behaviors will shrink (like Critic behavior in France or Creator behavior in the UK) — and that we need to adapt our social media marketing programs to these changes in behavior. It means that even successful social media programs can — and must — be updated to continue to thrive.

Forrester clients can read the full report, European Social Technographics® 2010: The Rise Of The Joiners And The Conversationalists. We’ll have the 2010 data loaded into our free online Social Technographics Profile tool soon as well. And I’ve love to hear from everyone in the comments below: How are you adapting to these changes and making use of this new type of social behavior?