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Yes, of course, as a marketer, I heard about such a tool as call tracking, and we can say with confidence that this useful tool is in great demand in the market because of its effectiveness and usefulness. In addition, the big plus of call tracking is that it is ideal for many fields, including for small business - https://callgear.com/industries/small-business/ [callgear.com]
The main point is that you can track and better understand your client. Find out which advertising company influenced his coming to you and other factors. All this will help to collect additional analytics and debug work to maximum efficiency.

Thancs for description, what call tracking is. 
I think. instrument like this can be really useful in my work. I will try to use it.