Just as the Internet has brought the information closer to people, it has made every bit of information likely to have readers. No matter how obscure the topic, people will always try to find interesting information. Many sports make for excellent sites, if you are a big fan of a soccer- or football team; why not make a blog about it? If the team is large enough – and you target clever keywords – you will have visitors reading your text, and hopefully clicking an ad or two. Some of the most visited web pages about sports are just blogs, and most of them do very well using affiliate programs to make money online.
The same applies to most sports; Golf, hockey, cricket or even bowling can be a good topic for a site, just make sure to evaluate the competition for each intended keyword before you start, as these are very popular sports, thus making the topic and keywords more popular online as well.
If you have more specific hobbies - such as woodworking, jewelry, pottery or any other craft – the competition are not nearly as hard, but the amount of potential visitors may be lower. No matter what niche you are targeting, make sure there are ways of monetizing your site. There are many different ways, but the most common ones are affiliate programs or contextual advertising.
If you are targeting a very small niche, contextual advertising will be likely to bring you only a small amount for each click, due to the lack of bidding for those keywords. Similarly, this can work FOR you if you are bidding for visitors using contextual ads. Finding an affiliate program in small niches may or may not be hard, but if you find a good one, you will almost always make more with a traditional program, than you would with contextual advertising.
With affiliate programs, you are able to present your visitors with products you decide fitting for them, with contextual ads, the script does this for you. While this is (or should be) highly relevant ads, you still lack the control over the specific ads. With sites in small niches – or with low amount of traffic – the importance of higher commissions are necessary to keep the site profitable. Getting only a few cents per click will not cut it if you only have a few visitors per day, but if you can present them all with a product they want, you can make quite a bit of money.