See a need, fill the need. What better way to notice a need than when you chronically have it. And that is what "scratching your own itch" business philosophy is about. Feel the bite of a need, then build a business around it.
Many of the biggest businesses in the world started that way. Steve Jobs and Steve Wozniak wanted a personal computer and not a time shared access to an expensive public computer. That need made them create Apple Computers (now Apple Inc.). AirBnB started same way, the founders were trying to fix a personal problem they had and ended up creating a new business that disrupted an entire industry.
The best business ideas come from needs you have experienced first hand. You become your own business' first customer and evaluator. You can easily know when you've built a good solution/product since you are your own business client.
My refocusing of my business to web based product/solution is a result of my scratching my own itch. There are many web-based solutions I would like to see -- stock analysis apps, fraud reporting app, celebrity (both persons and businesses) rating apps, simple for-Nigerians only apps, etc. And rather than find someone else to build them, I plan to build them myself. I also have bought a lot of IoT devices/components; planning to use them to build Nigerian centric smart products. Home automation devices, single function cheap devices, children tracking devices to help parents when to go to crowded malls and other public places. I have lots of ideas borne out of needs I have a first hand experience with, and I intend to build solutions for them.
If I were interested in microfinance banking services, I would structure a product that is an exact replica of "ajo". You can pick how many "owo" you want (cycle of payment). So there can be 3, 6 and 12 cycles. It is going to be exactly like the one the market women do and come with interest. It will sell like pure water: familiar and plain.