Google Answers not the first failue in this genre...

1999: LookSmart Live!
1999: GuruNet / Answers.com
2000: Yahoo Experts
2002: LiveAdvice

All tried to provide the same service as Google Answers, and all failed. A good article on past and current competitors here.

No commentators have really suggested the real reason Google shut it down. My best guess is that it is a combination of many things:

- no Google staff member wanted to work on it
- it didn't warrant home page promotion, but without that it had few visitors
- it went against the "information for free" principle
- technical difficulties! (somehow they were unable to email customers when their question was answered - very embarassing)
- low profits - although it should have easily made money, it probably did not have the same ROI as other Google services
- were tired of being poorly compared to the Answers service of Yahoo

In the hands of a research company targeting big business, or another search engine that would promote the results appropriately, Google Answers could thrive.... but Google would be too proud to sell it.