Basically the value proposition is providing more granular privacy controls for Twitter; you can decide who can see a piece of content or not.<p>I think it's a good idea, although I probably won't use it since I don't have enough followers on Twitter in each group that I can nicely classify as: "family", "co-workers", "hockey club", but that may change over time as more people adopt Twitter and I am able to label all these people.<p>Right now, when I want to share something, Facebook is still my primary since most of the people I know and keep in touch with is on Facebook. For me, Twitter is for some people I know, but mostly a discovery tool to find new people I previously did not know. That said, if I have private content, I am unlikely to post it on Twitter. Because if I did want to share it to people I know, they're all on Facebook and there's privacy controls there.<p>(Just sharing my use case)<p>Entrepreneur to entrepreneur, I am just concerned that Twitter will decide after you have gained traction that "hey, people _do_ want more privacy controls, and they build in privacy controls and give it away free for everybody" aka what Amazon Web Services did; knee-capping startups that innovated around the edges and giving away their value proposition for free.<p>Any sane founder will keep such a threat in mind, however much of a stretch it may seem.<p>It'd be nice if you have a way to hedge against this risk, imho.<p>- or -<p>you could be lucky and get acquired, like how Twitter bought the Mixer Labs for the value their created for Twitter users.