- Apple, Samsung, LG, and Google have supplanted a wide range of consumer products with modern cell phones. Point-and-shoot cameras, some prosumer cameras, low-end document scanners, household telephones, PDAs, small flashlights, small voice recorders, portable tape and CD players, car CD players (via wired or BT connectivity), portable DVD players, boom boxes (via Bluetooth speakers), car GPS navigation systems, compasses (to some extent), pocket notebooks, planners (to some extent), a large segment of the wristwatch and pocket watch market, pocket calculators, professional scientific and graphing calculators, walkie-talkies and handheld radios (not completely though), portable electronic games and some game consoles... those are a few of the big ones.

- There is no type of brick-and-mortar store in any branch of retail or auction that hasn’t been hit hard by Amazon and eBay. Additionally, all the B2B businesses in the retail supply/service chain have been hit hard as either their clients suffer or they themselves lose business to Amazon.

I could go on. The world is a completely different place than what it was 20 years ago.

An extreme case of "software eating the world," basically.

That is what makes them so difficult to defend against. They don't behave like market incumbents and they compete with a very different set of skills than are seen in the markets they enter. They also tend to narrowly target the most profitable parts of the sector first instead of the entire value chain and expand from there, which rapidly reduces the profit incumbents could use to invest in a defense.

And in fairness, a lot of sectors are gravy trains for the incumbents. They haven't had to work hard for profits, never mind survival, in a very long time. They also spend the first few years in a state of total denial about the threat when one of these companies shows up.