I just invited a friend of mine to Hubski who has promised to give it a try later today -- I'll tag him once he makes an account. He is NOT a Redditor (though he lurks) or an active Twitterer, and he uses Facebook less than I do. Previously, I'd mostly invited disgruntled Redditors to Hubski.

I challenge you to think of someone who has an interesting passion (my friend's is geology as it relates to climate change, as well as indie music) who is NOT already an active social news site user, disgruntled or otherwise, and invite them to Hubski. Introduce them here, if they join.