A study of the WebmasterWorld states that 75% of all blogs on Google's blogspot are spam.

According to this study the top 15 doorway domains consist of 14 domains, where the spam percentage is over 74%. This means that in four search results of current study, three sites turned out to be spam. The researchers scanned 1000 most searched queries: 'phentermine' on blogspot.com and the query 'ringtone' on hometown.aol.com. The WebmasterWorld experts easily identified more than a half of the search results as spam.