“Free” answers the price question. It does not answer the usefulness question. A reader still needs to know what they receive, why it matters and whether accepting it creates another commitment.
Describe the deliverable
Replace vague value language with a concrete output. A website review could include a recorded walkthrough, three prioritised issues and an explanation of what to fix first. That is easier to evaluate than a “high-value consultation” with no defined result.
If you attach a monetary value, have a defensible basis for it. A price invented for the promotion does not tell the customer anything useful. Often, a specific description is stronger than a large crossed-out number.
Explain the commercial relationship
A free diagnostic might introduce a paid service. That relationship can be stated openly. Tell the customer which part is included and whether they will receive a proposal afterwards. Do not make them complete a booking before discovering an unavoidable charge.
The ACCC's guidance warns that the overall impression of an offer can be misleading even when conditions appear in fine print. The practical editorial rule is simple: a qualification that changes the meaning of the offer belongs beside the offer.
Give the free thing a complete job
A useful sample helps someone make progress even if they never buy. It could help them identify the right problem, compare options or recognise that your paid service is not suitable. That is a more credible introduction than withholding the essential answer until the sales call.
Review the offer from first impression through delivery. Can the customer explain what they are receiving, what they owe and what happens next? If any of those answers are unclear, changing “free” to “at no cost” will not fix the offer.