An investment system in marketing systems for a business can significantly increase sales and profitability, but requires smart management of referrals, recording the source of each lead, returning to interested customers in a timely manner and documenting outputs and sales. Working with Excel files, daily reporting to the team manager, WhatsApp messages, registration in customer software, these are all tools that can help, but in the long run you need systems that know how to talk to each other, don't miss information, and give you all the control.