We do need to spend a decent amount of time in studying the target audience and also categorizing the audience so we can start spending on marketing. Also marketing is not a piece of pie anymore because of the cut-throat competition.
Hiring some good marketing agency might do the thing but it will be expensive and we will have to be prepared to spend a fortune on the marketing team even before we get the results. No results coming out will mean there is something wrong with the product or the marketing team is not working efficiently.
Quality products builds marketing and yield reward. Great products suffer little at the initial stage of marketing before making lots of sales. However, not everyone could set up a product, they prefer to do it with already existing ones. Which still turn out great, and in such a means, the producers would be spending more on ads while the individual investors get to add minor efforts in marketing since the product is already accepted by many consumers, example, breweries.
As for inventors, a quality marketing agency would have to suck them so deeply financially to reach high sales, considering the high competition in the speedy return of most industries to market more on the slightest drop of revenue.