Selling yourself is an Idiom which means sell your Ideas confidently to convince others and if you can convince anyone in selling your Ideas, you can perfectly sell anything to anyone. 

The entire WORLD is living these phenomena of SELLING fundamental.

The theory says, A person is never so sure about his/her needs & wants but always so sure about his/her desires. Based on that desires, if an idea comes across which create some possibilities of fulfilling those desires, the transaction of SELLING starts & further ends up with its completion. Here SELLING yourself (salesperson) is (selling anything) to that person of having a desire.

Buying a home, Buying a car, Investment- Deposit plans, Buying insurance plans, Investment in Land, Gold, Equity or so on.

Selling yourself= Selling an idea=Selling a dream=Selling Organization=Selling Legacy=Selling Economy=Selling Future=Selling Growth=Selling Anything

It's a very vast topic to discuss but very interesting & never-ending topic to research upon. I would like to put a pause here & want your opinions to share on this topic for our further discussion.