Since Yahoo! decided to buy itself many million cool, popular teens, we've been wondering just how much the billion dollar purchase is working out. Are they clicking ads? And more importantly, just how popular did Tumblr make its historically square parent company? It was murky before, and now they're making it even more opaque.

As recently as November, Tumblr allowed Quantcast, a traffic-measuring service, to "directly measure" its daily, weekly, and monthly traffic figures. This "direct" measurement is inexact (generally considered a lowball), but it's good for comparing against other sites, and provides at least a good sketch how many people regularly use a website. It was this Quantcast feed that BuzzFeed used in two incisive posts, which suggested this past fall that Tumblr isn't just stagnant, but possibly shrinking. Neither Yahoo! nor Tumblr will talk specifics about the latter's popularity—generally not a good sign—which leaves Quantcast as the next best source.

Not anymore! Quantcast now says Tumblr's "Traffic data has been hidden by the owner." Like irksome parents of gifted children, internet companies will almost always boast about their little princes and princesses if there's good news to spill—or at least find some way to fluff the numbers, a la Snapchat. But this isn't obfuscation or spin, it's just shutting off the lights—and secrecy will prevent exactly zero people from continuing to speculate about Tumblr's traffic.

Tumblr has not immediately replied to a question about its Quantcast measurements, and I'll update if they do.