If you create a Blog with the primary purpose for such online business advertising google adsense, Amazon, or other ad programs similar to it, then before making a blog you should consider the theme of your blog first. The theme of a blog has a close relationship with the large number of visitors to your blog. The more attractive a theme of the blog then the blog more likely to be visited by many people and that means increase the odds of these blogs to be successful in ads programs. Of course, the election blog theme does not only consider the commercial aspect, but also must consider the interests and areas of expertise you mastered. I think this is actually very important, because we can write good articles if the material is indeed an area under our control.
The theme of a blog are represented by keywords and to your blog easily searchable by many people then you should choose the most searched keywords and try the rivalry (with other website / blog) that as low as possible. If we choose the best-selling keywords searched by people but also many websites / blogs that use these keywords on the opportunities of our blogs to be in the top ranks in search engines is small because of the competition.
To determine the competition's most sought-after keywords, you can use Google adwords Tools which can be accessed at the address http://adwords.google.com/select/keywordtoolexternal.
Good Luck!
