Yahoo, Inc. has announced that it has cleared the way to purchase the social website Tumblr for a cool $1.1 billion.

The Yahoo board approved the deal in a conference call on May 17, but by Sunday, it wasn’t clear whether Tumblr had accepted the offer. Yahoo reports that it will hold a press conference as soon as Monday to make an announcement on the matter.

Tumblr, a social media site that combined blogging with a sharable, crowd sourced platform, was founded by David Karp and Marco Arment in 2007 and built a quick following.

Already many Tumblr users are lamenting the decision to sell out to Yahoo. On May 19, the website Mashable posted a piece about the “upheaval over Yahoo’s rumored Tumblr acquisition” revealing some users disgust at Tumblr for selling out to the corporate giant.

Additionally, a day previously, tech writer Peter Kafka warned Yahoo that Tumblr was beset with a “porn problem” as many of its users post photos and subject matter that aren’t safe for work.

Kafka also notes that the racy content was not even a violation of Tumblr’s terms of service agreement as the site is set up so that users can “flag” NSFW blogs if they like, though the terms do state that porn videos are unwanted content.

A separate report by Kevin Eklund finds that many of Tumblr’s top bloggers offer pornographic images.

Tumblr founder David Karp reported last year that his site had earned $13 million in revenue, has 117 million unique web users, and had 12 million smartphone visitors–up from 4 million earlier in the year.

If the sale is completed, Yahoo is likely to increase advertisements on the service to increase revenue.

Interestingly, the Wall Street Journal notes that if the sale for $1.1 billion goes through, that Yahoo would be “paying a premium.” In the fall of 2011, Journal notes, the Tumblr was only valued at $800 million.