The term splog was popularized around mid August 2005 when it was first used by Mark Cuban, but appears to have been used a few times before for describing spam blogs going back to about 2003. Mark Cuban, owner of the Dallas Mavericks and majority owner of IceRocket, went online with a complaint that Google's blogging service lacks sufficient controls to prevent automated software from creating splogs in bulk. He wrote in his blog: "The blogosphere was hit by a blogspot.com splogbomb. Someone did the inevitable and wrote a script that created blog after blog and post after post." He added that he was not talking about a hundred blogs with a hundred posts each. He was referring to what could easily turn into tens of thousands of blogs pinging out millions of posts!
Content is usually nonsense or text stolen from other websites with an unusually high frequency of links to sites associated with the splog creator that are often useless and contain gibberish and are full of links to other web sites that spammers are trying to promote; also known as spamalanche.