Why writing about your small village with just a thousand villagers when you could be writing about a topic with one hundred million unique visitors a month!
To find out which topics have the most traffic, first you need to use Google keyword tool. This tool is free to use and will tell you how many monthly visitors each topic has plus how much advertisers are paying to reach that audience.
With Google keyword tool you have full intelligence about how your business will perform under those keywords. It gives you the audience, the income and even the competition.
Topics with high traffic, expensinve advertisers and little competition are the best ones to write about. For example, the work book has a lot of traffic but little competition but advertisers are also not in the mood to spend that much with this keyword yet considering the competition this keyword is worth writing about.
Second, very high traffic keywords such as music are not worth writing about not because of the traffic or the money, but because the competition is too stiff. Unless you love music as well as you have a site full of music and video clips, you are just not going to make it with words because those searching for music want to listen and see and not read.
Finally if you see a topic with little traffic and little competition, see how much advertisers are willing to pay per click. If the price is above one dollar, maybe it is worth the time. Test it before make it a full time business.