If you search in Google you will get hundreds of profitable blog niche ideas. But only very few bloggers succeeds.
To be a successful blogger in long-term, you have to choose the niche of your blog wisely.
There are 3 main factors to be considered when choosing the niche.
1) What is the primary purpose of blogging?
Generally there are two category of bloggers.
First one is, people who are blogging out of passion for their topic and eventually monetize it. Here the primary focus is not money. In such cases, the question of choosing a niche is irrelevant as they blog on the topic they are passionate about.
Second one is, people who start blogging only to make money out of it. Such people will not have a clear idea on which topic they should choose for the blog. Some will start with a multi-topic blog and some other with a particular niche.
2) Choose a niche with free flow of contents
You should be able to write anything and everything about the topic that you choose as the niche. Otherwise after 5 to 10 posts you will run out of ideas if you choose a niche only by looking monetization and the high CPC keywords.
You should be able to generate blog contents easily. This is an important step as the consistency in publishing the post have to maintained for a successful blog.
Of course, research can be done to get new topic ideas on the niche, but choose only a niche that you are expert in explaining.
3) Competition level of the niche
Always select a low competition niche. It will fetch organic traffic easily.
First, do a research about the keywords, using the Google Keyword planner tool to find out how competitive are the keywords or the topics that you choose. Then shortlist the niches with low or medium level of competition.
Finally, select one with better CPC and your knowledge about the topic.
So keep in mind the above 3 factors for choosing a niche and get ready to hit the publish button.