From Seo Wiki - Search Engine Optimization and Programming Languages
Niche blogging is the act of creating a blog with the intent of using it to market to a particular niche market. While it could be argued that all blogs are, in some form, a niche blog, the term as it applies to marketing refers to a particular kind of blog.
Usually, niche blogs will contain advertisements of some sort (pay-per-click or products or both). In some cases, the purpose of the niche blog is to incite the reader into visiting another website which may then attempt to sell the reader a product or service.
Niche blogs are sometimes referred to as splogs, but this is a misnomer. Even though the desired end result for the niche blogger is to make money, the niche blog itself often contains valuable information. Most pay-per-click advertising is content-sensitive, so it is vital to the niche blogger to have useful content that is related to the chosen niche.
Features of niche blogging
The popularity of niche blogging among new marketers can be attributed to several factors, including cost, adaptability and generating traffic.
The most significant reason for the popularity of niche blogging is the cost. Niche bloggers can quickly and easily create a blog for free. In this way, the marketer can determine the viability of the selected niche before making a large investment of time and money.
Because people's interests often change over time, it is important for a successful marketer to stay up-to-date on current trends. By using free services, the niche blogger can quickly adapt to the changing market and create a new blog marketed to that niche.
Adaptability also refers to the ability to update the information on the niche blog at will. A great feature of blogs is the ability to add new articles on a daily, or more frequent, basis
Also each post is akin to a stand alone webpage allowing the blogger to create articles independent of each other.
In order for a website to be profitable, it must have visitors. Normal websites require search engine optimization or paid advertisement in order to gain visitors. Blog services like Blogger, on the other hand, incorporate Really Simple Syndication (RSS). Using this technology, the niche blogger can inform various online directories of the blog's existence. They, in turn, provide links to the blog. Visitors to these directories are then exposed to the blog's listing and may choose to visit the blog. Thus, the directories act as a marketing tool for the niche blogger.
DeBare, Ilana. "Blogging tough way to make money - but here's how". http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/09/12/BUJSRRJ9H.DTL. Retrieved 2007-09-18.