The Internet is widely used by political parties to report events and to send messages to the voting population. Politicians used digital media (websites, blogs, bulletin boards/lists, and chat/instant messaging) in recent elections, together with traditional media (television, newspapers, rallies, etc.). Political blogs represent not only an additional communication channel but also an instrument for spreading editorial content and messages, virally infecting more traditional media channels. A key task for any political party or politician is to make the blog understandable and easy to read as a first step to ignite and spread the right viral effect. To reach this goal, writers must consider both their content and their target audience. This article measures the readability of the text of a political blog to provide insight on the effectiveness of viral communication using blogs. The Beppegrillo.it blog was analyzed from January 2005 to May 2012 and is a unique example of a political blog using a single official media. This blog switched in the period of the study from being a personal blog to a political blog. The posts were divided into two different phases: the former were intended to discuss political topics and were written by a not-yet-political contributor; the latter were posts written by an active politician. Content analysis using simple word and sentence counts for every year of posts was undertaken, along with a readability analysis using the Microsoft Word Spelling and Grammar function, and both the Gunning Fog Index and the Gulpease Index. The two different phases were compared to determine if any change occurred in readability, complexity of the text, and volume of communication. In this way, we can explore the differences in the communication techniques used in the political field unofficially and then officially. Finally, our findings indicate that levels of readability of communications, particularly among broad-based audiences, may be deteriorating significantly when the blog becomes a political one and the communication becomes more institutional. Copyright © 2013 John Wiley & Sons, Ltd.