Technorati reports that 30,000 - 40,000 new blogs are being created each day.
According to David Sifry, part of growth of new blogs created each day is due to an increase in spam blogs.
What are spam blogs? They are fake blogs that are created by robots in order to foster link farms, attempted search engine optimization, or drive traffic through to advertising or affiliate sites.
They contain robot-generated posts made up of random words, with title linking back to blogger's own pages.
Many bloggers see them as a way of getting their pages indexed quickly by Google and other search engines.
Sifry estimates that about 20% of aggregate pings Technorati receives are from spam blogs. Most of this fake blog spam comes from hosted services or from specific IP addresses.
Those in SEO world are well aware of this. There are even services like Blogburner that encourage creation of spammy blogs and spam-pinging to get your sites indexed quickly.
As a blogging evangelist, I wholeheartedly recommend blogging as an SEO tactic. But I also emphasize that you should use your blog for more than just SEO.
At Spam Squashing Summit, blog services decided to collaborate to report and combat blog-spamming.
Technorati currently claims to catch about 90% of spam and remove it from index. They also notify blog hosting operators.
But I believe that they are fighting a losing battle. As I write this there are software and robots being created that will create spam-blogs more efficiently and in ways that will be harder to detect.
The SEO "black hats" are always far ahead of technology and safeguards that these services can put in place.