I've been reading Stephan Ward's excellent book on the history of journalism ethics. From page 118:
Everything stems from periodicity. The publication of a weekly or daily paper has to overcome economic, technical, and editorial problems. But, once established, the periodical then has to maintain a precarious contract of "trust" and presumed reliability with readers. Each week, newsbooks had to attract readers and assure them of their reliable news service and cogent opinion. They had to provide the sorts of information that readers demanded, in the style and tone expected. Commercial competition added to the pressure, prompting editors to characterize competitors as untrustworthy and devoid of editorial standards. Periodic news publishing "set up a continuing relationship... between reader, printer, and the originator of information" (from Smith, p 9). The publisher of the occasional broadside or pamphlet lacked a constant and close relationship with a recognizable readership. [My emphasis]
This resonates with what I've been saying here about aggregates: it is only through periodically-updated media 'properties' that media establish direct relationships with audiences; properties define, and are partly defined by, the consumption communities that make up their audiences. These relationships are formed through habits, which are in turn based on socially-shared practices.
Properties are 'aggregates' in two senses: they are destinations that always offer their visitors a selection of unexpected, surprising content; and they also aggregate in time, giving the recurrent practice a coherence that reflects the curator's voice, over time building a more or less coherent ongoing narrative about the world. It is not that a brand alone can define a personality; it is this voice and this narrative that define a media brand.
What is currently shaking media radically is the sudden ease with which anyone can set up a media destination (in the sense above), and not just the ease in publishing and consuming 'content', or in finding the content one 'wants'. Without destinations content would go unknown, undesired, unlooked-for, and hence not found.