Some believe that Sales stops after closing the deal, Do you think so?

It does not end and customer engagement activities continues for future mutual benefits.

Sales does not stop after deal is closed. Sales after service is important. Trust, commitment, and satisfaction are three pillars of good business relationship and a continues interaction is necessary to build this relationship. 

1. The sales doesnt end with closing the deal.In Accounting language, both in Accounting Standards9 and IFRS, it emphazises on risk and rewards being transferred to the customer which means the control should have been passed to the customer and the seller should not have any hand on the good/asset.  The work of sales department ends only when the the goods have reached the customer and the customer is the proper owner of the same

No, it does not stop.

Sales are responsible for making sure all process  are completed and the client is happy.

Building relationships takes time and is based on trust. The ultimate aim of your approach should be to create a relationship whereby the client refers to you for consultation on certain matters. Sales should arrange a further meeting to discuss future business at the earliest possible opportunity.

AGREED WITH MY SMART FRIEND DIVYESH,,,, HE IS RIGHT,,, SALES IS A SCINCE SO THE SUBJECT IS MOVING ON .................   PRE SALES & POST SALES ARE THE TODAYS COMPETITIVE MARKET REQUIREMENTS............

I feel sales does not stop by closing a deal. Actually it has started and will have to continue.

close the sale once you observe buying singals stop selling and close the sale a common mistake that can lose a sale is to continue to sell and offer products\\services after the customer has already indicated that they are willing to make the purchase

No... That's why we have a term called AFTER SALES, the sales team should follow up on how a product or service is working for the customer. This practice will enable the sales team to know more on how they could promote their services or products better. Doing a follow up will also let the consumers feel that they are important and they are prioritized.

It really depends on what you're selling (electronics, medical appliances or food?) and who you are selling to (B2C or B2C, high-value added or one-time customer etc.). It also depends on the size of company and the number of individual designations or people for specific tasks. 

Generally speaking the act of selling does stop at closing a deal, but the job of salesman does not stop there.

An example of what follows up sales is CRM-for-sales (Customer Relations Management); which is basically concerned with the registration, re-call, analysis & reporting of customer insights and intelligence during the7 stages of a typical sales-cycle that is vital for the next approach of same or similar customer and for evaluation of the sales process, from lead generation, to qualification, to conversion, quotation, closing and asking for referrals (Even up and until payment-behaviour if you really want to be thorough)!

No. I don't think so.