Real-time presales chat gives customers the ability to chat with a sales rep on the site without disconnecting their network connection and without picking up the phone. This is crucial for people shopping from work. The chat takes place in real time with text. Typically, the sales rep will be able to push pages to the customer, showing the products they are having trouble finding. The alternatives to pre-sales chat are email and phone support.
Email takes too long.
You want to respond to a customer's questions while that customer is still in the mood to buy. Also, email isn't interactive. If the customer has more questions or if you need more information to answer the question, then the dialog can drag on. Phone support is expensive and annoying. Only about a fifth of Americans have more than one phone line in their homes.