Tumblr’s Adult Fare Accounts For 11.4% Of Site’s Top 200K Domains, Adult Sites Are Leading Category Of Referrals

How much of Tumblr is porn, and what is Yahoo going to do about it? On the latter, Yahoo CEO Marissa Mayer spoke to its plans for addressing content that is not “brand safe” earlier this morning on a call about its $1.1 billion acquisition of the site, saying that Yahoo will need to have “good tools for retargeting,” and will “monetize in a way that is tasteful.” But as for the former, it’s often been something of a black box – there simply wasn’t publicly available data.

However, now, we may have some answers. According to an analysis of Tumblr’s 200,000 most-visited domains, 22,775 of them are adult – or 11.4 percent. The analysis was performed by web measurement firm SimilarGroup, a company which raised $2.5 million earlier this year with the intention of competing with Alexa’s stronghold in web rankings.

The measurement firm analyzed the volume of visits to these adult subdomains, and found that 16.6 percent of the traffic that visits Tumblr takes place on adult blogs.

In addition, 22.37 percent of incoming referral traffic from external sites to Tumblr is from adult websites, making that the leading category for referrals. Meanwhile, 8.02 percent of outbound traffic from Tumblr goes to adult websites.

Below are some screenshots from SimilarWeb Pro, which shows Tumblr data from the past year (May 2012 to April 2013), detailing the breakdown of referrals and outgoing links:



Neither Tumblr nor Yahoo responded to requests for comment, as of publication time.

Tumblr’s secret to successful growth back in the early days, was in fact, its adult content. In some circles (read: mainstream users, typically men), it’s what the site is still known for today. Anecdotally, this is the kind of thing I hear all the time when I bring up Tumblr among members of this not-so-tech-savvy group: “Oh, you mean that porn site?” Uh-huh.

To be fair, any site that relies on user-generated content is going to have a porn problem – even Instagram and Pinterest get dirty at times. But Tumblr seems to be better known for it than the others.

Still, Mayer is right – it’s a matter of targeting Tumblr’s ads correctly when they do go live, to make sure that porn and brands are not living side-by-side on the same page.

All Things D broke down why Tumblr’s porn stash is not a problem for Yahoo, explaining that Tumblr’s ads appear in the sidebar of the Dashboard – the home page feed where people follow the blogs they’re following. Another type of advertisement called “spotlight” ads, promotes Tumblr blogs in a directory of suggested account. Neither of these types of ads are hitting the users who come to Tumblr for the adult fare.

That’s because, users in search of Tumblr’s adult content are usually doing just that – searching. (And with the “Safe Search” filter turned off, course.) These folks don’t see Tumblr’s ads now unless they actually subscribe to adult sites. However, that doesn’t necessarily mean they’ll be immune to all the ads in the future.

Mayer also discussed today Yahoo’s future advertising plans, saying that it may work with bloggers to provide ads that run with their permission, and plans to integrate Yahoo’s search functionality on Tumblr’s site, too. In other words, Yahoo will need to be very careful when rolling out its additional ad formats to make sure brands and pornography don’t get too tangled up.

After all, it would only take one screenshot of some supposedly family-friendly household name next to a video of “hott girlz doing xyz” to cause major controversy and possibly harm to Tumblr’s own brand.

Currently, brands marketing on Tumblr aren’t worried about the adult content, says Hayes Davis, CEO of Union Metrics, whose company now tracks over a 100 million events on Tumblr per day, including posts, reblogs and likes, out of Tumblr’s over 107 million blogs and 50 billion total blogs.

“Tumblr is becoming a strategically important marketing channel for these brands, and they are making large investments in the platform. Just this year, we’ve signed up brands and agencies that represent myriad industries, including higher education, entertainment, fashion and beauty, sports, consumer products, travel, technology, news and retail,” says Davis.

Marketers love the viral engagement and staying power around branded content on Tumblr, he explains, saying that posts live for far longer on the site than on other networks. That data point was also hinted at in Tumblr’s own reveal today that out of the 50 billion blog posts on the site today, only 5 billion are original content – the rest, presumably, being the re-blogs (re-sharing another’s content on your own blog).

But as for the NSFW content, according to Union Metrics, “it frankly never comes up in any of our discussions.”

Time will tell if that still remains the case in the future.

Also of note? Mayer just blogged this: