How do you approach a customer once you have the data? I imagine you will build a relationship with your customers eventually, but when you're just getting star

How do you approach a customer once you have the data? I imagine you will build a relationship with your customers eventually, but when you're just getting started, do you just ask a potential customer via mail/email/phone if they want to meet and discuss your data of company X? I'm also curious as to the level of "polish" that you are expected to provide. Let's say you know how many widgets Acme sold this last quarter. Is that by itself enough information, or would you need to calculate projected expenses / other stuff to actually be able to deliver an earnings estimate? What if you just had projected revenue? Thank you!