How Pennsylvania firms actually get work
Other firms are the channel
Pennsylvania has an unusually large number of small practices serving a county or a pair of counties, and for many of them the most valuable source of matters is other lawyers. A firm that does not handle a particular kind of work sends it down the corridor or across the county line, and expects something back in due course. That arrangement is durable, informal, and almost never written down anywhere the firm can look at it.
Recording each referring firm as a relationship, with the matters that came from it and the matters you sent to it, changes the conversation from impression to fact. It also makes the relationship survivable: when the partner who maintained it is unavailable for a month, somebody else can pick it up because the history is on a screen rather than in a memory.
County shapes everything downstream
Which county a matter sits in decides local procedure, the court involved and which of your lawyers appears. A firm covering a spread of counties that treats this as a free-text note ends up routing enquiries by whoever answered, which produces the familiar pattern of a matter being handed around the firm for two days before reaching the person who could have taken it immediately.
As a structured field it drives routing and reporting. Volume by county tells you where your work genuinely comes from, and a county producing enquiries you keep declining is a coverage decision rather than a nuisance.