"Everyone is a salesperson" How ?

Yes ,

as Sales is offering what you have to convince the other one to get you have

and  this appears in some situtions in our life for examples, 

1-Everyone is offering their skills and qualifiction to employers to convince employers to hire them 

2- Parents also use this concpet with thier children as rewarding them if they did what parents asked them to do like eat your food and i will give you sweets 

Yes everyone is.  First what is a salesperson? A salesperson needs to believe in the product they are selling. They need the curiosity and drive to not only know the fine details of their product but also the industry they are selling in.  They need to stay current in industry innovations and direction.  They need to be creative enough to think of uses and advantages of their product outside of mainstream uses to sell in areas others haven't thought of.  A salesperson is one who understands personalities and cultures and has a respect for both. They should be organized and detail oriented to follow through and ensure their customer is taken care of before, during and after the sale. A happy customer is a repeat customer or an excellent contact for networking. A good salesperson doesn't think of the current sale but future sales and plan for achieving them. These are the traits of a salesperson but they are also the traits of a good employee. Every person in a company represents that company. The secretary, the CEO, the customer service representative, shipping and receiving, marketing, Vice President; everyone. Everyone who interacts with a customer gives that customer an impression of that company and that will influence their choice; sometimes more so than the product itself. Those that don't interact with customers are supporting those who do and can help or hamper their success. A secretary that answers the phone professionally and is helpful and follows through is selling the company. A shipping department that gets a shipment out accurately and in a timely manner promotes future sales.  Everyone in a company is a sales person when viewed in this light. 

Because everyone sells themselves to their employers by finding a job, or with entrepreneurs they sell their business ideas to investors.

everyone is! ( some better than the others)

we selll on day to day basis - be it a product, an idea , a thought, even an emotion. we all do know how to. we are born with this need to convince our people of our thoughts eventually making us sellers. tricky bit is, to sell something that you are least inclined to or remotely interested in.

everyone is a sales person - yes

but can every one sell - no!

Most people don’t want to be in “sales.” This term tends to have a negative reaction. But why should it? “Nothing happens until somebody sells something” – an old quote from Arthur H. Motley, and still very true today. All of your employees rely on your company selling something, whether directly or down the line. So each employee needs to be aware of his or her place in the sales process and marketing cycle.

showing how useful and important is the product 

how the product will effect his life style

well product information will save the deal

A Sales person is a person with certain attributes and constituents. Not everyone has those attributes. Some can learn and adapt but others cannot. Sales is a Talent, and the successful sale people succeed while others try to shadow them.

However every department and every employee has to sell themselves first to the HR. As in they have to prove that they are the right ones for the job. Later if employed they have to promote and sell their ideas.

Yes, Everyone is a sales person. Sales is all about the communication and sharing your idea. Everyone is offering their skills and qualifiction to employers to convince employers to hire them

A salesperson goes to the buyer for the sale product.Similarly, a person goes to others for his own needs.

Each company need to contact with clients, they must have the opportunity to make a positive impact about the company so he will have employers under the company name to show the quality and offers of the company so the normal employers which will face the clients are the salesperson that company had certified on.

by having a helpful attitude, you as a employer need to show the offers of the company your work for and give a good background of the company to the client, so here you are called a salesperson.

Yes, First before you sell and doing a sales talk towards client or a customer you must know your product that you are going to sell. In that way you may now consider yourself as a sales person. Convincing Power , Sincerity and Selling Techniques should applied. Kidding aside; Like Courting someone!  Selling yourself to her/him it will take time but then still you tried to offer and waiting for the magic word "YES"