Some industries, like the athletic shoe industry, are dominated by a small number of firms with strong brands. these industries are difficult to break into without spending heavily on advertising. the barrier to entry that the firms in these types of industries have erected is referred to as

The barrier to entry that the firms in these types of industries have erected is referred to as "product differentiation".

Product differentiation is a promoting procedure that features the contrasts between items. Separation hopes to make an item more alluring by standing out its one of a kind characteristics from other contending items. Successful product differentiation makes an upper hand for the item's seller, as clients see these items as being extraordinary or predominant.  

Product differentiation can be as straightforward as bundling the products inventively, or as detailed as joining new utilitarian highlights.

the assumption the narrator makes in this excerpt is that the messages he heards were going to hurt the narrator's mom; the narrator just springs in to action. the narrator doesn't specify in this excerpt why he believes that the messages present a problem that requires protection.