Yeah, I had this discussion with someone recently. Companies of that size can drown out competition for years, decades even, by operating at a loss (or just not making much profit at all) because they have numerous revenue streams and the pre-existing highly-profitable sources can subsidize the not-so-profitable new one. Once you have a nice big customer base, tighten the screws and wring money out of the users now that they are captive. The rate at which that process occurs varies, but it's basically inevitable, especially for publicly-traded corps.