In my opinion, it is, because it can show investors that the team is ready to bring huge results and has future plans.
As an example - KickCity, event platform where each user is rewarded for event promotion. You can try it today. More information you can find here https://medium.com/@kickcity_io/kickcity-public-beta-5aa66fafc5c7
The product is only important? You can't even do anything if you don't have a product.
This is your interpretation of the question, but it's ok I get your point. Still I am saying that you should have something that convinces people to finance your endeavors. It can be an idea, but in the best case scenario it is a product.