In the telecom industry/ISP infrastructure business, the very best sales people are much more like business intelligence/market research people. They know where everyone's infrastructure is in a given region, for fiber cable routes, right of way, POPs, and what carrier is riding on top of which one. Knowing who owns and operates the underlying dark fiber route, DWDM systems, regen huts and similar on a multi state region is what gives them the power to be so effective.
Being able to operate from a position of confidence and assurance on "who has what, where" is a very powerful tool. Then, when communicating with potential customers (particularly where it's one ISP entering into a relationship with another ISP), they can offer the correct product for what the customer is looking for. Or, if they can't, they can quickly say "sorry no we can't do that, we don't have any of our own stuff there, and we can't get there by an NNI".
Being able to operate from a position of confidence and assurance on "who has what, where" is a very powerful tool. Then, when communicating with potential customers (particularly where it's one ISP entering into a relationship with another ISP), they can offer the correct product for what the customer is looking for. Or, if they can't, they can quickly say "sorry no we can't do that, we don't have any of our own stuff there, and we can't get there by an NNI".