6. A computer-implemented method for providing an answer to a question left unanswered in a discussion forum, the computer-implemented method comprising: as implemented by one or more computing devices configured with specific executable instructions, identifying a question in a first discussion forum stored in a data store; determining that the first discussion forum does not include an answer to the question; determining a second discussion forum in which to present the question, wherein the second discussion forum is more likely than the first discussion forum to result in an answer to the question; presenting the question in the second discussion forum based at least in part on the determination that the first discussion forum does not include an answer to the question; receiving one or more responses to the question in the second discussion forum; determining whether one of the one or more responses comprises a good answer to the question; and when the determination is that the one of the one or more responses in the second discussion forum comprises a good answer, notifying a user that the question has received a good answer, wherein the user submitted the question in the first discussion forum.
6. A computer-implemented method for providing an answer to a question left unanswered in a discussion forum, the computer-implemented method comprising: as implemented by one or more computing devices configured with specific executable instructions, identifying a question in a first discussion forum stored in a data store; determining that the first discussion forum does not include an answer to the question; determining a second discussion forum in which to present the question, wherein the second discussion forum is more likely than the first discussion forum to result in an answer to the question; presenting the question in the second discussion forum based at least in part on the determination that the first discussion forum does not include an answer to the question; receiving one or more responses to the question in the second discussion forum; determining whether one of the one or more responses comprises a good answer to the question; and when the determination is that the one of the one or more responses in the second discussion forum comprises a good answer, notifying a user that the question has received a good answer, wherein the user submitted the question in the first discussion forum. 10. The computer-implemented method of claim 6 , wherein the first discussion forum and the second discussion forum are each associated with at least one of an item, a category, a sub-category, a community, and a tag.