Since Yahoo! bought Tumblr back in May, at least two metrics show some sort of decline in usage, notes BuzzFeed, which could suggest that CEO Marissa Mayer wasn't telling the truth about her intentions and that Yahoo! really did ruin the service. On the other hand, there may be a general decline in use of the blogging service that has nothing to do with the new ownership.

Whatever the reasons behind it, both Quantcast and BuzzFeed data show a decline in Tumblr's usage since that fateful day in May. Here's Quantcast:

And the BuzzFeed data:

"This data, and Quantcast’s, suggests that Tumblr’s presence on the internet, or at least a major part of it, isn’t growing, but shrinking," writes BuzzFeed's John Herrman. That is indeed true, though it's less clear that Yahoo!'s the culprit.

Since the acquisition, Yahoo! has certainly roiled Tumblr users. Many were upset at news of the acquisition, fearing that David Karp's brainchild would be destroyed by Yahoo! corporate masters. Some of this panic was, just, well, panic. Yahoo!'s presence, however, has changed the service in ways that may have turned off users. Its porn crackdown and subsequent censorship of certain LGBT hashtags, for one, has a lot of people crying censorship. The site has made some other tweaks, like re-adding the analytics bar, that has some Tumblr users upset

But, looking deeper into the numbers, it's still not possible to point the finger directly at Yahoo!. This chart from Herrman shows peak traffic in November, which means Tumblr's decline was well under way by the time Yahoo! swept in:

Without more information, it's hard to tell if a dorky brand ruined something cool. It's just as easy to believe that the cool kids had already moved on. 

Update: Tumblr notes that third party metrics don't "provide a full picture," a spokesperson told The Atlantic Wire. "Particularly as they can't capture mobile app usage, time spent, or all AJAX page loads. In fact, we're super excited about the accelerating growth we're seeing in Tumblr's apps following the launch of our new Explore tab and the 'no registration required.'"