A good number of the top technology blogs might love reviewing gadgets and software, but its the ad revenue that keeps them running, writes WinExtra.
Steve Hudson has looked at the portion of Technorati's Top 100 blogs that are focused on technology and found that 21 of 34 accept advertising in some form. That has led, in his opinion, to more of a focus on practices that will protect that ad income. That's based on the logic that popularity is determined by incoming links and the more popular a blog is the more it can ask from advertisers.

Loren Baker at Search Engine Land points out that advertising income is allowing many people who couldn't otherwise afford to do so to engage full time in their passion for blogging about a niche industry.

That niche attracts loyal, dedicated readers - a group that advertisers will pay a premium in some cases to reach.