Market research is one of the 3 big things for brand builders, other than brand management and strategic communication. Market research sets the landscape and environment for you to build your brand and advertising. Some companies, especially the smaller ones, ignore market research at their own peril. They assumed understanding of the target consumers, whom may turn out to be quite different at times.
Research can be used to test on before and after campaign impacts. This will clearly inform you of the impact the campaign has on motivating your target consumers to buy your product. You can use consumer research early in new product development process, to determine the right attributes that your products should have to meet consumer needs.
You can understand your environment better, such as how the customers perceive of brands in a category. You can check on their current perception towards competitor brands, and how your brand stacks up vs. competition. You can then refine your positioning to compete better.
It is very important to use market research to determine the top category attributes, such as whitening and cleaning efficacy for laundry. A new brand may make the mistake of assuming a position in a niche such as making clothes easy to iron after washing, which may be a low priority attribute that consumers do not pay much focus on. It is better to face the big players with a slight variation on cleaning and whitening power, than to occupy a niche that is hardly lucrative.