Answer:
Problems: many times ideas emerge as a way to solve existing problems or satisfying unsatisfied needs.
Technological innovations: new technologies can inspire new ideas or ways to do business, e.g. Amazon would not exist without the internet.
Change: changes in society, new regulations or laws also result in new ideas, e.g. the lockdown resulting from the current health crisis resulted in many business coming up with new ideas to change the way they work.