I do wonder if it could be argued (maybe even in the current monopoly case against google) whether youtube engaged in predatory or below-cost pricing in order to drive out all of its competitors, establish a monopoly, and now use that monopoly in order to "raise prices" i.e. increase the amount of ads on its service in order to maximize its profit margins.
Although this does seem to be the business plan of basically every startup out there. Get VC funding, run at a loss and burn through money but gain a monopoly market share, and once you've done that you can raise your prices and have a profit margin that far exceeds what should be normal.