[closetCS]

As much as a Google replacement would be great for competition, it would be extremely difficult. Google was able to scale with the web gradually through anti spam and proprietary software, but a new competitor would struggle to reach such a needed scale so quickly

Tl;dr: High cost of entry for newcomers

[imron]

People said the same thing about AltaVista.

[matt_the_bass]

Agreed but I don’t think this is quite the same case. Back then Alta Vista pretty much only offered search as a value to its users. Google certainly started there but offers a lot more than just search to its users. Only one service had to be overthrown to overcome AV. Lots of services would need to be overcome to overthrow google.

(Note I said “users” not “customers”)

[maxxxxx]

You just need to overthrow the ad business and Google will have a huge problem.