A few things you need to build a search engine: 1. something that *understands* the question 2. something that *understands* content (web pages) 3.

A few things you need to build a search engine: 1. something that *understands* the question 2. something that *understands* content (web pages) 3. something that can match the output of 1 and 2 very fast and at scale 4. a way to generate revenue out of the whole thing without bothering the user or perverting the output of 1,2 and 3 In the case of Google, they have a fairly good implementation of #1,#2 and #3 and they used to have found a decent compromise for #4. In the last 5 years though, they have completely eff'd up #3 because of the pressure that comes standard with large US-based corps: the next quarter EPS is the only thing that matters, and long-term growth is not something wall street is interested in. Burn a patch of forest, grow something on the ashes-fertilized soil for a few years and move on to the next patch when the soil is permanently dead.