Some blog owners delete or rename a blog, without proper planning - and later regret their action. Some spammers track blog name availability - particularly with blog names that contain "English" (and some non English) language words. If a spammer discovers that a given blog name has recently become available, he will publish a stub blog to that name - and later, add spammy content. Why is a spammer interested in recently available names?
What Blogger won't tell you