The blogosphere is made up of all blogs and their interconnections. The term implies that blogs exist together as a connected community (or as a collection of connected communities) or as a social networking service in which everyday authors can publish their opinions. Since the term has been coined, it has been referenced in a number of media and is also used to refer to the internet.
The term was coined on September 10, 1999 by Brad L. Graham, as a joke. It was re-coined in 2002 by William Quick, and was quickly adopted and propagated by the warblog community. The term resembles the older word logosphere (from Greek logos meaning word, and sphere, interpreted as world), "the world of words", the universe of discourse.
Despite the term's humorous intent, CNN, the BBC, and National Public Radio's programs Morning Edition, Day To Day, and All Things Considered have used it several times to discuss public opinion. A number of media outlets in recent years have started treating the blogosphere as a gauge of public opinion, and it has been cited in both academic and non-academic work as evidence of rising or falling resistance to globalization, voter fatigue, and many other phenomena, and also in reference to identifying influential bloggers and "familiar strangers" in the blogosphere.
In 1999, Pyra Labs opened blogging to the masses by simplifying the process of creating and maintaining personal web spaces. Prior to the creation of Pyra's "Blogger", the number of blogs in existence was thought to be less than one hundred, which was thought to be the fetal stage of Blogosphere. Blogger meant the birth of blogosphere. In 2005, a Gallup poll showed that a third of Internet users read blogs at least on occasion, and in May 2006, a study showed that there were over forty-two million bloggers contributing to the blogosphere. With less than 1 million blogs in existence at the start of 2003, the number of blogs had doubled in size every six months through 2006.
In 2011, it was estimated that there are more than 158 million identified blogs, with more than 1 million new posts being produced by the blogosphere each day.
In a 2010 Technorati study, 36% of bloggers reported some sort of income from their blogs, most often in the form of ad revenue. This shows a steady increase from their 2009 report, in which 28% of the blogging world reported their blog as a source of income, with the mean annual income from advertisements at $42,548. Other common sources of blog-related income are paid speaking engagements and paid postings. Paid postings may be subject to rules on clearly disclosing commercial advertisements as such (regulated by, for example, the Federal Trade Commission in the US and the Advertising Standards Authority in the UK).
Within the blogosphere, several sub-communities have developed. These communities are largely divided by genre. Blogs are often identified by a specific genre or topic, such as travel or politics.