Go Sell What You Cannot Produce
I had a mentor tell me years ago to build a sales page for a product I didn't have yet. He said to promote it, advertise it, tell everyone you know about it. He was 100% serious. He said, "If it starts selling and you confirm it's a winner, then build it. The worse that can happen is you have to give people their money back."
That stayed with me. I now have customers come to me in the planning stages for a new product. What do you think I tell them? I tell them, "Let's try selling it. Let's sell it without having built it yet." You can consider offering it as a beta, signing people up for a soon to be release product or even out right selling it as if it did exist. The point is to focus on selling the benefits, addressing the objections and confirming you have something people will buy.
Over the years, I've run into clients that love complexity. It's like they want to lay the tracks from Miami to Seattle, consider all potential hazards they can encounter well past Texas and never think, "What if I never make it out of Florida." If their idea doesn't work, they've spent so much money and effort. What a waste!
I'm an engineer by training. Math, calculations and numbers are my thing. At at my core, I'm suspicious. I don't like and think it's a bad decisions going on a hunch or a gut feel. I believe you must test an idea, see what the true market thinks about it and take the next step based on measurable results.
I've had customers build complete products. This was a huge undertaking. Then they built a comprehensive sales funnels beginning to end. They went out and start promoting the thing and got nothing. The initial concept or idea didn't work. There wasn't a demand for what they had to offer. The problem is the found out they had a flop only after have investing all that time and money.
Now those of you who like to dot all the "i"s and slash all the "t"s will feel really uncomfortable about this, but this approach works. If your idea fails (and it really could), you've only lost what it took to test the idea. If it's a winner (and you'll know it's a winner if your experiment says it is), you've confirmed that and you can proceed knowing from measurable facts that it will sell.
Hope this helps!