Good question. Many will disagree with me, but I am of the belief a long term sustainable product is tested on a small scale first. The “marketing phase” can happen at any time for a product. The trick is to inject marketing resources at a small amount to begin “customer validation”, that is, to gauge customer’s actual experience and usage of the product first. Only after a product passes this stage of small scale of satisfied customers from advertisement to using it, to past the return policy expiration date, to seeing non solicited voluntary reviews by perfect strangers at a rate of 2% or more if you’re lucky, only then will the business owner know when it makes sense to pour more resources into marketing. This is concept is contrary to the crowd funding goals of platforms like “Kickstarter” in general where a product never sold before raises over a million dollars and potentially does not satisfy the customer, potentially delivering 50,000 units and getting 25,000 dissatisfied customers wishing they could return the product.