Whether or not a business works comes down to two things: (1) are there customers who want the value you provide and (2) is the amount they are willing to pay for that value more than the cost of you providing it?

This hasn't changed in the history of business. What has changed is how easy it is for you to test these two things.

Fear of "failure" often restricts us to judging whether an opportunity will work out in our heads. This is silly. The world is our laboratory.

So, the answer: find a way to develop the idea into the cheapest, easiest possible test to determine whether this is the case. Then go out there and do it. If it fails, great. If it succeeds, even greater. The goal is to use the market to determine whether you have a real business idea on your hands, or just some fantasy you've made up.