I agree... this may hurt/help Google group making. Either people will add non-contributors to a group and get bored with others' lack of contribution, and by extention Google circles. (To combat this, it'd be great if Google helped curate or edit circles, like with listservs. Non-content posters would be flagged for me and I could opt into auto-removing non-contributors or just being notified that they are diluting my circle.) Or, it will result in better curated lists of people -- similar to twitter, where you really only want to follow someone (and up your following count) based on the quality of their content.