You can track how clients find your business using new ‘Source’ and ‘Referrer’ fields.
Under Clients > Details, each client record now includes ‘Source’ and ‘Referrer’ fields that allow you to record where the client heard about you. If a new client was referred by a colleague or other client, you can record this in the ‘Referrer’ field in 
order to ensure you thank them later. And if a client found you on Yelp or saw your flyer at the local coffee shop, you can record that in the ‘Source’ field.
Both are basic text fields, giving you the flexibility to capture anything you want.