InstaASS; Photo-Sharing Service Adds Direct Messages Instagram just made a major chess move on Twitter by adding a private messaging feature. We know what goes on in those DM’s stays in those DM’s unless some one leaks a screen shot.From the New York Times’ Bits Blog: The popular photo-sharing app Instagram introduced on Thursday a messaging service that would let users send private photos and videos to their friends directly. Why did they add it? Because everyone on Instagram is pissed they haven’t been getting laid. Seriously. [Kevin Systrom, a founder and the chief executive of the company] said that the feature is meant to let people start a private conversation around a particular photograph or video. Anyway, the feature seems useful, if not exactly “revolutionary,” as Systrom tried to claim. It’s prettily designed, easy to use, and is likely to come in handy for photos that you want to share with a group of people but not with the whole world. Or, sure, for se*ts, if you’re not into the whole ephemerality thing. From a business-strategy standpoint, it’s a great defensive maneuver against upstart private-messaging apps like Whatsapp and Path.