Do you think having sales experience that is not related to digital marketing is useful nowadays?

Sales is different to digital marketing. In the real marketing world, it would be better to have some understanding of how sales work - however, in digital marketing, it is all about how engaging your audience is and how you can drive your sales online. The digital strategy should revolve around engaging your audience and developing an online fan base which in turn would boost online/in-store sales.

I believe it helps. Every digital marketer should know that his effort should be converted into leads which importance sales person will understand for sure.

We cannot say useless to any kind of experience. Furthermore, sales experience is much beneficial if you are entering in the field of digital marketing. 

What is purpose of marketing ? Ofcourse generate sales. As a marketing professional you need to reach your audience as a sales person to explain your offer precisely and make them understand your product or service.

For me, it's a yes! Businesses are not always on digital world so sales experience in real world is necessary. Also, digital marketing is aiming to hit sales target so it might always relative to each other.

 As a marketing professional you need to reach your audience as a sales person to explain your offer, I think that in now days sale got another level but the experience of everything is not good or bad for.

In my point of view, both are different and diversified fields, but the task is same to having attracted more clinets towards our product. whatever the Marketing you ppl are doing, having quality product to get more and more clients in the nowadays competitive market. 

Although digital marketing being a separate field my belief is that it is a sub section of marketing where as a digital marketer should have skills in sales which will be the base in building up a good digital marketing platform

Definately. This is because there still exists a magnificient percentage of today's market that has not completely adopted to the digital migration. Therefore, to reach such a market, sales experience that is not related to digital marketing plays a very key role. 

digital marketing is a great tool to sell a product. 

I believe the experience helps. We have to understand that before the digital media came to be, we had (and still have) offline, in-person, and one to one sales marketing.

Having a sales experience generates the instinct of the marketer to what kind of lifestyle the market in front of them is and if they are likely to buy the product; and we need that kind of knowledge of market beahaviour when it comes to digital marketing.