Business is all about the paying customer! Depending on your business type, those customers can take on many shapes and descriptions. They can be another business that you sell your product, service or advertising space to but it can also be a consumer product or service.
No matter what business you are in; without paying customers you will eventually fail. This may seem overly simple but it is amazing to me the number of pitches I have heard as an investor or consultant where the business model was not focused on sales. The pitch would include awesome things about what they could do or how great their tech was but nothing about how they were going to sell it. Yes, they would say that the market size is X and we will make millions by capturing Y% of the market but they never told me how. By the way, I never set through a pitch that did not state they were going to make millions; please skip this in your presentation, it does not make the impression you think it does. It seems like marketing and sales are dismissed as givens when it is my experience that this is the lifeblood of the company. You could have the cure for cancer but if you can not take it to market and get people to participate it is useless.
Marketing and sales is all about getting people involved and participating. You are competing for their time which is at a premium. Even if you are selling a consumable product that the customer has to have such as shampoo; you must have something that gets them to take the time to look at your product and pick it over the other options. Maybe that is your packaging! Maybe it is that your price is lower than everyone else! Whatever your model you must get grab the customer.
Once you have grabbed the customer; hang on for dear life! There are multiple studies that discuss how much cheaper it is to sell to an existing customer than to acquire a new one. The less you spend the more you profit!
You need to have a marketing and sales plan that lays out the cost and expected results so you can measure what is working and what is not. Then adjust! Business 101: Sales Solves all! I have purchased many companies over the years that were insolvent or bankrupt but they had sales. These companies were easy to turn around because the hard part was done; it was just a matter of bad management practices.