In business offline and online business must implement an efficient customer service.
Many online companies are questions or concerns of visitors to your website and do not pay due attention to these comments.
Simply lose the opportunity to do business with these people.
If a person asks a question of a service or product is because they really are interested and need more details of what you are watching and are interested to decide to buy.
It is best to have a FAQ page where you identify the questions that you mostly do on the product or service you sell and go collecting responses on a web page accessible to people.
Also, surely, there will be cases of questions which need further customization of responses and in that case, you should respond within 24 hours and within 48 hours.
In my opinion this is the most recommended for Internet businesses that do not have a lot of questions.
If you want something more advanced see if you can implement a live chat to have direct contact with your visitors and you can also consider the possibility of responding via Skype. Everything depends on the demand of questions you made in your business over the Internet.