Episode 90 of the Kobo Writing Life Podcast features an interview with Dennis Weichman, (AKA, Mr. W.), a retired math teacher who has brought his passion for teaching and tutoring into the digital realm with YouTube channel and study guides published to Kobo.

Mr W. is interviewed by KWL Director Mark Lefebvre. In the interview, they discuss:

How, after he retired in 1998, Dennis began tutoring students in math and he recognized something that was lacking for many of the people he was working with were enough examples.
His compilation of those examples into a print workbook that was made available via a local school uniform company’s retail store
The request from students for him to compile more math books for even more grades
The various high school math subjects covered and how they are all based on the Ontario curriculum
How he created math tutorial videos and the YouTube channel with more than 50 videos and 100,000 views from 150 different countries
Advice for those who are either frightened of or are not comfortable with math
Relating math to things that people understand or are interested in/passionate about
The “hand-written” appearance of the math examples and how that personalizes the content for users
How Dennis had to work really hard at math himself, and how that perhaps affected the way that he teaches it to others
The former student that helped Dennis get his books into eBook format

You can watch the full video on YouTube here.

After the interview, Mark talks about writing specifically for a niche market, and uses both Mr W.'s example as well as a personal example to outline the process.

His talk includes how focusing on a niche market/niche audience usually involves identifying and resolving a problem or an issue for that target audience as well as the application of personal experience and knowledge as well as personal passion to creating and publishing that book.