Be the best in its class.
Have a unique set of attributes.
Be the cheapest.
If a brand does not "fit" one of these perceptions, then it has a "fuzzy" value proposition for most customers. Brands exist in the mind and represent a collection of experiences over time. The mind is like a dripping sponge of brand value perceptions. The only way anything new can get in is to replace what already exists with a newer brand value perception.
Typically, brands lose positions as the result of the introduction of faster, better or cheaper solutions.
Every marketer must compare their company's unique resources with specific customer's changing requirements and select those that the company can satisfy better than competitors. When this is done well, and promoted effectively, a brand will "own" a position in the mind of a certain set of customers and prospects.
Every market consists of customers with strong and weak perceptions of competitor's levels of satisfying their specific requirements. Marketing in its simplest form is analyzing customer requirements in depth and then modifying product offerings and related value propositions so that they "fit" better with the requirements of a certain segment of the market than their competitors.