I suspect we'll never see any detailed discussion on the issues you raise, Temis, because many of those variables will differ from show to show based on the financial models present.
But some generalizations could be made. I'm pretty sure that sf/f shows - and any sort of serialized show - benefits more from downloads/DVD sales than sitcoms, police procedurals and reality shows. You can see that in the difference between the list of top-rated shows vs the list of top downloads or DVD sales.
Since this is about the financial basis of the entertainment biz, someone is making those generalizations now, in great detail, and giving them to the boss to make decisions on. They just won't share, darnit!
One other suspicion of mine: the sudden upsurge in sf/f series as a percentage of overall new shows is due to those generalizations. Somebody has realized that even if a new show sucks in the Neilsens, and most of them do, that sf/f shows can still be salvaged by downloads and DVD sales. Also, the international market is an unknown factor, but I'm thinking that helps sf/f as well.
It's interesting that Chuck
, with its marginal ratings from last season, has already gotten a full season order from NBC, even though the season hasn't even begun. That's probably partly due to NBC's overall desperation, but if Chuck
didn't have genre appeal, would they have been so generous?