The number 3 is the most important. It is impossible to generate sales without advertising and marketing, irrespective of selling online or offline. Your product needs to reach the target customer or have visibility in the market and marketing and advertising can help you do that.
Exactly! Your business is never going anywhere without constant advertisement and promotion of your business product and services. This is because that is the only way you can be able to make your business a visible in the market for your potential customers to always keep patronizing whatever you are selling so that your business is going to keep growing.