[gcthomas]

Google has grown by using ad revenue to buy comoetitors or companies that do something interesting, then squeeze them for every penny of profit or dump them.

Google has a dominant search engine, a browser and massively intrusive ad placement system threaded through everything they offer. Gmail was a Hotmail clone. Android, Fitbit, Maps, Nest, and Google Earth were acquired. YouTube was bought after it out competed Google's offering. Even the advertising tech was acquired, with AdMob, DoubleClick invented outside Google.

They are dominant mostly because they have not been bothered by antitrust actions. That, at least, looks like it might happen sometime relatively soon.