Ask most business owners where last month's customers came from and you get a list of platforms. Instagram. Google. Referrals. Those are places, not sources, and the difference matters the moment you have to decide where next month's budget goes.
A platform is not a source
Two people both arrive through Instagram. One saw a post from a friend who tagged you. The other saw a paid advertisement, ignored it, searched your name three days later, and came through your profile. The platform is the same. What actually earned the enquiry is not, and only one of them is something you can buy more of.
Last click is the cheapest lie in marketing
Whatever tool you use will hand you the last thing a customer touched before they contacted you. That is easy to record and it is usually not the thing that persuaded them. The last click is often your own name typed into a search box, which tells you that the customer already knew you and tells you nothing about how.
You do not need attribution modelling to fix this. You need one more question at the point of enquiry.
Ask, in their words, and write it down
Add one field to the form and one line to the phone script: how did you hear about us? Leave it open rather than offering a dropdown of your own guesses. The answers will be untidy and that is the value. "My sister used you last year" and "I saw the video about the clinic prices" are different sources, and no analytics tool will ever tell you either.
Record it against the customer, not in a note somebody writes and loses. If it does not live where the deal lives, it is not data, it is a memory.
Then count what the answers led to
At the end of the month, group the enquiries by what people actually said, and count two things per group: how many enquiries, and how many became customers. A source that sends many enquiries and few customers is not a good source, however good the traffic looks.
This is the point where the conversation about spend becomes a conversation about evidence. You are no longer comparing platforms, you are comparing what different kinds of introduction are worth.
Give it three months before you act
One month of this is an anecdote. Three months is a pattern you can spend against. Start recording now precisely so that the decision you have to make next quarter is made with something better than the last click and a strong opinion.