Generally business offerings are divided into products and services.
Products are the tangible things we buy – furniture, cars, computers, food, clothes.
Services are intangible things we buy – health care, financial consultations, a fitness class, cleaning services.
These distinctions become slightly blurred when you consider information products that have become popular on the market in recent years in the form of e-books and e-courses. They are considered a product, but are not as tangible as your traditional “hard” products. Another blurring of the boundaries is the fact the products often come with a service attached, and services often come with a product attached. For example if you are purchasing a new car (product), you will receive a service from the car salesman as they run through the pros and cons of various cars and help you find the right car for you. You may also receive free or discounted mechanical services as part of your purchase. Another example is going to see a naturopath to discuss a health condition. They will provide you with a service to diagnose and advise you about your condition, and will also often encourage you to purchase products as well.
Some things are Easier to Sell
Some products and services are more essential than others (eg. food is more essential than jewelery); but being essential alone, doesn't make them easier to sell. If a product or service is in over supply; you will be competing with many other suppliers; and the quantity of sales may be spread thinly. When there are very few suppliers, competition decreases. When you are supplying something unique, and it is unavailable elsewhere; your ability to sell will not be affected by competition at all; but the importance of the product to customers will still be a strong factor.
Another important factor is "visibility". If people are unaware of what you are selling; you won't make sales, even if competition is low and the thing you are swelling is important. The customer needs to be aware of the product's existance, where they can get it, and most importantly; why it is going to be of value to them.