Step #1: Know how to help them find their answers - MLS/Transaction Managers/Forms Programs/ Financial records (check stubs, etc.)
Step #2: Look back at their expenses and tax receipts.
Step #3: Teach them to keep a marketing record (file of samples of what they did and where they spent their money)
Step #4: Look at results with them. How many transactions can be directly linked back to which marketing efforts? It can be more than one but all of them need to be categorized.
Step #5: Compare how much was spent with the GCI result and the net result.
Step #6: Have them rate how hard they were to convert. Was a web lead harder than a listing referral from a past customer? That will help you identify what training they need specifically and what training is needed by your office if a pattern emerges.