Evidence intake sounds like a formality. In practice it is the part of the sequence that decides whether anything afterwards is worth reading, because a diagnosis can only be as good as the material it is built from.
What gets collected is mostly unglamorous. Closed and lost opportunities with the stated reason and the real one where they differ. The last two quarters of inbound enquiries and what the sender actually asked. Proposal documents as they were sent, not as they were meant to read. Call recordings if they exist. The pages a buyer lands on and what they do next. Whatever numbers the business already reports, along with the definition each one is calculated from.
What does not count
Opinion about the buyer is collected and labelled as opinion. It is useful, because the gap between what a firm believes about its buyers and what the record shows is itself a finding, and sometimes the largest one. It does not enter the baseline as evidence.
Testimonials do not count either. A quotation a client agreed to give is evidence that they were willing to be quoted. It is weak evidence about why they bought, because the reasons people give after a decision are reconstructed rather than recorded.
Why it is done before the interviews
Reading the record first changes the questions. An interview that starts from a stated pattern is a different conversation from one that starts from a blank page, and the second kind reliably produces the story the business already tells itself.
Where the record is thin, that gets written into the baseline as a limit on confidence rather than covered over. A measurement that hides its own gaps is worth less than one that names them, because the second can be improved and the first can only be believed or not.