It really depends. The problem is that once advertising become the primary drip of financial resources, the content begins to revolve around the needs, goals, and preferences of advertisers. Content that isn't seen as monetizable gets shown the door. Content that rails against consensus opinion or is anti-corporate gets shut down. Things that earn money get promoted at the expense of all else.

You can see this lucidly in the case of Bill O'Reilly. People had already known his deal for over a decade, but it wasn't until his ad dollars were pulled (after a public pressure campaign) that he was dethroned. That's an example of the kind of media system that is fostered by advertisement.

EDIT: changed 'decades' to 'over a decade'. https://www.rollingstone.com/politics/features/a-timeline-of...