Write down every topic that you are knowledgeable or passionate about. You'll have a much easier time making money from a blog you are interested in, rather than trying to write content you don't like because you think it will make money. Some examples are hobbies that you enjoy, your career, or some specific and miscellaneous knowledge that you have.
When I spoke to Preston Lee, the founder of Millo.co, for my podcast, he told me that he first learned how to start a blog on his train commute in to his day job. He had 40 minutes each way going to and from his full-time gig, and he used that time to write, design and create his blog that now brings in upwards of $15,000 a month in sponsorship revenue.
It’s hard to get noticed when you cover topics on a broad scale. Everyone has their own set of problems, and every blog is trying to solve them. What you need is a niche that will help you target a specific market in the broader topic your niche belongs in. It’s important for you to define your niche before you start blogging or in the early stages of your blog, at the very least.
Perhaps the most popular network for placing these types of ads is Google AdSense. With this program, you do not need to be in direct contact with advertisers; you simply place the banner on your site, Google chooses ads relevant to your content, and your viewers click on the ads. There are countless similar programs available if you find that AdSense doesn’t work for you, such as Chitika, Infolinks, and Media.net.