[tracker1]

I remember when Yahoo was a manual index, AltaVista was the best internet search, and Hotmail wasn't a MicroSoft owned company... when most email addresses were truly painful (anyone remember doing internet email via fidonet? compuserve?).

Google has now been king for a while, but if someone came out that did things clearly better, people aren't tethered.. even Facebook has its' upstart competition (that they keep buying off).

People are less tied to their services than you think.. yeah, plenty of people are still using yahoo mail, and others aol for email even... but few are dialing in and fewer still could remember their icq login if they tried.

[alexhu11]

Do users pay for any of those services you mentioned? This changes the dynamic completely by forcing the user to become engaged.

At the core AirBnB and Uber are selling commodities. They appear to be the lowest-cost producer because of their cost structure and scale. The price advantage alone is a high wall to scale.

Could another entrant come and improve the AirBnB or Uber experience 10x? Maybe. I wouldn't bet money on it though.