I’ve been going through the older essays of Clay Shirky after reading through Here Comes Everybody, and at one point he boils down the economics of publishing (or, content creation) to very simple terms.
Here it is:
The economics of content creation are in fact fairly simple. The two critical questions are “Does the support come from the reader, or from an advertiser, patron, or the creator?” and “Is the support mandatory or voluntary?”
The internet adds no new possibilities. Instead, it simply shifts both answers strongly to the right. It makes all user-supported schemes harder, and all subsidized schemes easier. It likewise makes collecting fees harder, and soliciting donations easier. And these effects are multiplicative. The internet makes collecting mandatory user fees much harder, and makes voluntarily subsidy much easier.
From Fame vs Fortune: Micropayments and Free Content, which is well worth a read.