Porn is still welcome at Tumblr. Amid the announcement that Yahoo! has just acquired the popular blogging site in a billion-dollar deal, CEO Marissa Mayer assured Tumblr members, including pornographers on the site, that they won't censure their accounts, promising "not to screw it up."

During the investor call announcing Yahoo's $1.1 billion acquisition of Tumblr on Monday, Mayer said that they would "let Tumblr be Tumbr," implying that they would allow adult content to continue on the Web site.

Replying to an investor who asked how the Web search giant would balance user and advertiser interests regarding content that is "not as brand safe as the rest of Yahoo," Mayer said that carefully targeted ad placement should dispel the concerns of marketers who might not be agreeable to place their product alongside explicit content.

She did not specifically mention pornography, but mentioned content that was not "brand safe."

"I think the richness and breadth of content available on Tumblr - even though it may not be as brand safe as what's on our site - is what's really exciting and allows us to reach even more users," she was quoted by the Huffington Post as saying.

"One of the ways to start measuring our growth story here is around traffic and users, and this obviously produces a lot of that. In terms of how to address advertisers' concerns around brand safety, we need to have good tools for targeting."

She also announced on her new Tumblr blog that founder David Karp will remain the head of the company.

"We promise not to screw it up. Tumblr is incredibly special and has a great thing going. We will operate Tumblr independently. David Karp will remain CEO. The product roadmap, their team, their wit and irreverence will all remain the same as will their mission to empower creators to make their best work and get it in front of the audience they deserve," she wrote, as if to appease naysayers of the new company structure.

"Yahoo! will help Tumblr get even better, faster."

The news that Yahoo! has acquired Tumblr has angered and concerned many of the blogging site's members. They are worried that Yahoo would inundate their blogs with ads and apply drastic changes to the Web site as a whole.

One Tumblr blogger named daydreaminthesky wrote: "Ewwwwwwww. Ads. I hate it already. Once they make it about money the originality of this site will be thrown out the window."

Another named blu3skiesarecalling humourously noted that they can accept Ms Mayer because "Omg guys the yahoo ceo's tumblr url is marissamayr.tumblr.com and she dropped the e because tumblr and flickr both have a missing e. She's cool we can accept her as her own."