When Google pulled its YouTube inventory back from AdX, it disabled something that represented 5 percent of its total YouTube sales. But Google is hardly alone. Facebook locked everything up; Amazon would rather shut sales down that give up its data; AOL, Yahoo hold their best inventory back so you can only buy it through their platforms. It’s all pretty simple: These companies have invested billions into their product, and they have no obligation to make other businesses rich on the back of their investments. It is called competitive advantage.