Is content really king?

Very few content websites have managed to be profitable. Even Facebook (the reigning king) does not boast big profitability. Linkedin, Youtube, Twitter and others are still in the red. Most of the web-based businesses that have managed to become real-life giants in the business world (like Amazon, eBay, google, etc) have managed to offer the consumers with a solution for something other than just content. Amazon and eBay obviously changed the way commerce is done. One might think, what about Google, google captures a massive long tail of advertizers from one end and a humungeous number of consumers on the other end because it offers the one thing everyone HAS to use when surfing the seas of the web, search. Content only websites like Digg and blogs or even twitter have yet to find a sustainable formula to generate revenue from the huge traffic they are enjoying. This does not seem to be happening soon though.