Google builds a search engine, forces the competition to start improving.
Google buys a webmail service, forces rapid improvements in the competition.
Google builds a browser, forces rapid improvements in the competition (Firefox).
Google buys a smartphone OS, competition already doing ok but probably tweaked some things.
Google starts building an inexpensive fiber network, makes incumbents sweat a little.
Google buys a smartphone manufacturer, forces competition to improve.
Next up, probably a mobile telco provider.
Google's thing seems to be improving the transfer and display of ads. Somehow they've turned that into a benefit to technology as a whole. It's a business model built on disruption.