In marketing, we always want to promote something distinct about our brand. It could be low price (if we are the low cost producer) or it must be about something for which buyers will pay a premium.  This is a lesson from years ago from Michael Porter.  

What we too often forget is that the marketing energy can be for the brand and/or for specific products/services. 

Most businesses can’t afford to spend both to create a potent parent and product in consumers’ minds.  Fidelity has done a great job in creating its green line to lift whatever else it promotes. Apple has established itself a special brand so does not need to emphasize anything special about given products beyond its features (though Apple often has done so anyway).

All too many brands, of course, have not established real differentiation in either the brand or the product.