I'm actually not following what Subjot does (can't understand via the text blurb) and I'm not enthusiastic about logging in on any new service via Facebook/Twitter. So I'll wait for now.
It's an ideal concept to sort various different interests of a single person interest into separate containers based on target audience. I think Google+ came close but their naming policy sucks. I wish they'd allow different identity/per-Circle, which could help resolve this issue. But in perspective, I should be able to target my audience based on their interest as I know best and vice-versa. Twitter is totally ineffective here to most degree.