Using the Long Tail concept, Mike Rundle of 9rules offers some excellent advice for bloggers especially the newcomers: "So many new blogs are trying to emulate their heroes on the Technorati 100 when they should actually forget about that and just develop their content and form their own niche, because the audience is already there waiting for them" - No matter how obscure your content subject or niche, there will always be an audience looking for your content.
According to Mike, most of the Technorati 100 bloggers are there because of external factors (marketing, word of mouth, author fame, notoriety, etc.) that have nothing to do with their content
"Scoble worked at Microsoft for awhile which gave him certain notoriety, Boing Boing has been around forever and is edited by veritable Internet superstars, TechCrunch rose to popularity because Michael was intimately involved in the startup scene before he started blogging and brought his connections with him"
Source: Niche Blog & The Long Tail of Content
Related: The Long Tail | Long Tail Wikipedia