Can anyone give me insights as to how websites like chacha.com / kgb.com are designed. What could be the components involved when a user sends out an sms and how is that question stored.
Should the question and answers be stored in a relational model or non relational?
There are many way to accomplish the same end and unless you have actually seen the code or communicated with the developers, there is vast room for speculation. To include an explaination of how all the feature work I think is outside of the realm of realistic expectations for a question posting on SO, but I will offer you this.
I believe there is a "normalized" database of questions that have a status of answered (yes/no). There is an interface developed that allows chacha or kgb answerers to:
1. Pull a queued unanswered question.
2. Research the question and send an answer siting a source.