You can do, or you can hire others to do, some sophisticated market research to ensure that your product or service will sell in certain areas. Of course, if it’s an online business opportunity, you can do plenty of your own research quite easily. You can look at what other websites are selling, whether it is a product or a service, and to a degree, you can see how popular they are.
If you need to get a loan for your business opportunity, you have several options. The SBA can direct you to several loan options, although they don’t lend money themselves. The SBA is a great place to start anyway, simply because they do have so many resources. They have a lot of statistical information that you might find helpful in your market research, and they have several free publications to help you along in your small business journey.