[Closi]

Well, I guess I'm really talking about the price of the service rather than the cost to run it really (i.e. what would be a competitive price for the service considering other offerings), but appreciate that the price has to be less than their costs.

Although my assumption (which could be incorrect) is that storage is not the main driver for cost. For Netflix and Spotify I assume their major cost would be licencing, which YouTube mostly gets to forgo. For YouTube, I would assume bandwidth / data transfer is the biggest factor.