Agreed that inside sales is different from outside sales but in outside sales also sales personnel need to understand the customer requirement and then approach with proper analysis and ground work..Its not about joking with client..client anyway has no time for your jokes be it inside sales or the outside sales,he just want the answers for the questions he has and how he can be benefited from your offering.
Now coming to cold calling be it inside sales or the outside sales it takes time and as you rightly said it will give results later on..

As pointed out, inside sales is much different than outside sales. In outside sales, we joke around, fun talk with clients which is less possible in inside sales as on other side of the phone, you are not able to understand the situation of your client. Your joke can be taken as sarcasm or so.
you need to be very precise, crisp and to the point as most of us do not like talking on phone.
Cold calling will not give you business in a day or two. It's kind of sowing the seeds which may or may not grow to give fruit. Results will come after long waiting.

Firstly we should know about inside sales-
In the process of inside sales,sales personnel reach customers by phone or online rather than travelling to meet them face-to-face.
This type of sales is generally difficult as compared to the outside sales as no face to face interaction is done,Sales personnel has to read & understand the potential client
by the way he interacts.

In case of cold calling sales personnel should do the research work as to how the prospecting company operates,its business & services so that they can pitch the product accordingly. At the same time it is important for the sales person to have sound knowledge about the company & its products.
Now when it comes to interaction it is essential for the sales person to be confident with good communication skills and sound knowledge of the relevant market scenario.
It is very important to generate the interest of the other person,which is possible only when the sales person act as the genuine consultant & understand his requirement &
not just interested in increasing his points.