Question? Where would I get a good ebook title

Well see I have been thinking of writing me a ebook. But I can't seem to come up with a good thesis or should I say foundation. I was going to try and write a book about how to make money online, but there is a huge amount of books that are all ready out there with such a title or thesis.What should I do to come up with somthing new and fresh ? Like somthing that everyone wants to read but has not heard about. What would you like to read people please explain in your commects and get back with me i seek information and am willing to give out anything i have learned to people who ask.I also been thinking about a dating book, are those a hot topic to write about will people buy? Will You give me your feedback please and thank you.