What's the best way to answer the 'Try to sell me this pen' sales interview question?

- Sell me this pen

- Good. Would you give me your autograph? 

-Yes, but I have no pens (answer interlocutor. He's put it to you).

- Then buy my 

you need to focus on

1-the Materials

2-how it comfortable to use

3-how it working for long time as the ink pipe is bigger than the normal one

4- how the clarity of the ink

5- the price is competitive

In my opinion, that is a pointless question that just puts the interviewee on the spot. It is no measure of that person's ability to sell a product. Typically a sales rep is educated about the product they are to sell and the industry techniques to do so. Asking someone to sell you a pen in a car sales position interview is completely irrelevant. As a manager I think I would have much more fundamental things to ask about and look for in that person. I recommend managers use the S.T.A.R interview technique for I think it is much more objective.  

After the release of a movie Rocket Singh, this question has become like a must for all sales/marketing interviews. All sales/marketing candidates should watch this movie before attending an interview ...

Just sell it. Do not hesitate to sell. This is a question normally asked to a person attending a sales job interview.