Make a note of it
There is a term called "noteworthy" that seems to be appropriate for the purposes of a sales interaction.
Source: Sales trainer/speaker Gerry Layo
By writing down some of the main points of the conversation, you will not only show the prospect/customer that you are listening and that you care, you will also show that what he/she is saying is worthy of making note of it.
Also, if you write down what they say word-for-word and how they say it (use quotes on these parts), then you will have a tool to use later in the sales process to assist in closing the sale.