Dallas Smythe (1981) is often cited as introducing a further key element to PE approaches to media, inverting the assumption central to prior approaches to PE which focussed upon meanings, messages and information as the central commodity which relates to media.
Dallas Smythe is the man who contends that the economic relationship, which is the primary driver of media as an industry, is one where audiences or more are sold to advertisers. For example, YouTube and Twitter are sources of media that use advertisements to get people's attention, like thumbnails. It's consistent, so the people in these websites need to make different thumbnails to keep that attention going. If they don't, then they lose that attention.