When it comes to raising money you must remember that risk is a perception. Your job is to drain the risk!
Below is a link to a resource I provide my investors. The 50 questions are specific to product design/development but the 15 categories are questions that apply to any industry.
If you can answer these questions about your deal you will have gone a long way to "drain the risk" for your investors and get funded.
Once you have answered the questions for your deal schedule a call with me and I can help you integrate the answers into your investor pitch.
1. Very clearly identify the problem you are solving
2. Identify how the team you've assembled will help solve the problem
3. Explain how the investor(s) will get their money back!
You don't need hundreds of customers but at least a few success stories are critical. You must prove the case for your concept.
I answered a very similar question to this one here: https://clarity.fm/a/436
In short, teams or a founder with prior success can raise *substantial* seed funding with little to no product. But generally speaking, it is always best to have some version of your product and some evidence of product/market fit for that product before raising seed capital.
The cost of getting to that stage has decreased so substantially that seed investors expect teams to be able to achieve that as evidence that they are competent, committed and able to achieve the minimum requirements for business success.