A good product or service will sell itself with the help of a good salesperson. The salesperson's job is to contact potential customers, learn what they need or want, and educate them about how the company they represent can be beneficial in providing solutions.
Salespeople who are trying to sell a product or service you don't want or need can be extremely annoying. There has long been a myth in American business that the right salesperson can sell anything to anyone. People (especially in this day and age) are very well educated and already know what they do and don't need.
If you're selling a product or service that people don't want and are hoping to find the perfect salesperson to convince suckers to pay for it, you are in for a big disappointment.