Primary category decides which searches you are allowed to win
One field constrains the entire query set your profile can be shown for.
Google maintains a fixed category taxonomy, and the primary category is used as a filter, not a hint. If it sits outside the set Google associates with a query, the rest of the profile does not get a vote.
The commonest error is choosing a category that is too broad in the belief it captures more. “Contractor” feels like it covers roofing, guttering and flat roofs; in practice “Roofing contractor” makes the clearer claim, and the broad choice leaves you competing with every trade in the borough.
How to test alternatives without guessing
- Read the ranked set first. For each money query, note the primary category on the profiles that rank. If none share yours, you have your answer before changing anything.
- Change one field, then stop. Category, name and address edits in one week make attribution impossible and invite re-verification.
- Watch the query mix, not the total. New terms in the searches breakdown are evidence; total views moving is not.
- Track from a grid. Your own results are personalised and measured from your desk; check from points spread across the area you serve.