Yahoo Inc. announced a $1.1 billion deal to buy blogging site Tumblr early today, and said it "promises not to screw it up," CNNMoney reported.

The deal will help Yahoo tap into the younger, active online user base at Tumblr, CNNMoney said. But the deal also raises concerns among some Tumblr fans that the site could end up being cluttered by ads that bring in billions of dollars a year to Yahoo. Tumblr CEO David Karp has resisted the use of traditional display advertising on Tumblr to this point.

 

To answer those worries, Yahoo said that Tumblr will be independently operated as a separate business with Karp staying on as CEO.

 

Tumblr has 300 million monthly unique visitors and 120,000 sign-ups every day, with about 900 posts a second. As big as that is, it is dwarfed by Yahoo, which posted revenue of about $5 billion last year and a profit of $825 million excluding special items. Yahoo had $5.4 billion in cash on its balance sheet, according to its most recent quarterly earnings statement. Read more.