> want to build a search engine its not enough to index the web
Yes it is. People by and large are just searching for sites.
Spell checking is easy, deep linking is easy enough to get something basic in place, answers/images/video are hardly mandatory. And business/map search I can get by buying data the same way Google did.
Google's search engine is better than Bing for example because its index is larger and its core search algorithm better. Everything else are all "nice to haves".
I can tell you don't have much experience working in search engines them. Search engines are all about tail. Even if you had just as good algos and index as Google, you likely won't have any chance to take market share because you will fail in, for example, local queries which constitutes 10-12% of all queries. Someone entering USPS tracking in search box won't see delivery time. Someone else entering flight number won't see its status. A kid entering 100+200 won't see answer. And so on. All these things matters. When comparing things people don't see what works, they see what doesn't work. Also what you say "easy", for example deep links, are typically significant multi-year large team efforts with large number of open questions and very active academic research.
Yes it is. People by and large are just searching for sites.
Spell checking is easy, deep linking is easy enough to get something basic in place, answers/images/video are hardly mandatory. And business/map search I can get by buying data the same way Google did.
Google's search engine is better than Bing for example because its index is larger and its core search algorithm better. Everything else are all "nice to haves".