The modern consumer is bombarded with brands they can choose from. As a result, consumers filter out most of the brands they see because the human mind simply cannot process all the information it’s exposed to, and it has to take shortcuts.
The one and only purpose of marketing is to build your brand’s availability so that, when a consumer is buying the category, they don’t filter out your brand.
Brand availability can be of two kinds:
The logical consequence is that Light buyers favor large brands, because large brands are (by definition) the ones that have built the most physical and mental availability.
In fact, the ideal scenario for your brand is to become so widely physically available that it’s always within reach and so prominently mentally available that it becomes synonymous with its entire category.
This was Coca-Cola’s mission: to always be within arm’s reach, literally and figuratively. They have largely succeeded in doing this through capillary distribution and consistent (see Advertising must be consistent), effective advertising.