During the sales talk, how to know which is especially valuable for the customer and persuade him deeply?

In a systematic selling dialog process there is a situation in sales discussion with customer which is reaching a common ground it is only possible when customers all requirements are met.It can be achieved only when you have rightly probed the customer,identified his/her needs   and attached  accordingly the right feature of your product to the benefit it provides to the customer.See among the various needs which you have identified from the customer which is the most important and emphasize on that and you surely will leave an impact.

Great answer by Mr.Alamgeer, I have nothing more to add.

Thanks

Agree with Mr. Hussain Hashmi answer