RockMelt, the social browser, raised another $30 million from blue-chip investors. I’m not sure why. Last fall, I wrote a piece on how browsers don’t matter as much as they once did, mostly from a supply-side perspective. My argument was that at one point browsers rivaled operating systems in their role in establishing technology platforms and APIs, but that nowadays platform players mostly built their ecosystems around sites, apps, and the web itself. VC Ben Horowitz, who’s a RockMelt investor, tries to make a case for browsers from the user perspective. Although I’m also a fan of feed-based UIs, I don’t see that RockMelt is fundamentally integrating them or search or doing cloud-based synchronization better than other applications. Likewise for the potential of integrating daily deals, as another RockMelt backer, Marc Andreessen, suggests. He also alludes to phone calling, and I suppose a unified communications hub could live in a browser. Though like all the other functions mentioned, it would take more than mere integration to be a powerful differentiator.