Short answer
Four numbers tell you: attributed phone calls, form enquiries, cost per enquiry, and what type of work is coming in. Impressions, sessions, bounce rate and keyword counts tell you nothing about whether the phone rang. Ask how many calls came in and what each cost.
Most plumbers I speak to have a folder of PDF reports and no real idea whether any of it worked. That is not their fault. It is what happens when reporting is designed to look like value rather than to answer a question.
The question that cuts through it
How many phone calls did my marketing produce last month, and what did each one cost?
Ask that. If nobody can answer it, nothing else in the report matters, because none of it connects to money coming in.
It is a fair question and a good agency will have the answer ready. An uncomfortable pause tells you what you need to know.
The four numbers that matter
1. Phone calls, attributed. Not total calls. Calls broken down by where they came from: the map, the website, the ads. This is the most important number in a plumbing business and it is the one most often missing.
2. Form enquiries, by source. Fewer than the calls for most plumbers, but they skew towards planned work, which often means better margins.
3. Cost per enquiry. Everything you spent divided by everything that came in. This is the number that tells you whether to spend more or less next month, and it is frequently left out because it invites an awkward question.
4. What type of work. Which services and which suburbs. Useful when you want more of one thing and less of another.
That is it. Four numbers, one page.
What gets reported instead
Impressions. How many times you appeared. Not how many people came, and certainly not how many rang.
Sessions and users. Visits to the site. Better, but still not phone calls.
Bounce rate. Frequently misunderstood, and for a plumber often meaningless. Somebody landing on your page, reading your number and ringing you registers as a bounce. That is a success being reported as a failure.
Keyword rankings. Useful as a diagnostic, but a position on a search you win no work from is a vanity number.
None of these are lies. They are simply not answers to the question you are paying to have answered.
Why the timing of tracking matters
Tracking needs to go in before the work starts, not after.
If it goes in during month one, month three has something honest to compare against. If it goes in during month three, all anybody can do is tell you a story about how things feel better now, and you have no way to check.
That asymmetry is exactly why some agencies are slow to set it up. Vague beats specific when the work has not gone well. It is also why tracking is the first thing that happens here, before a cent goes anywhere else.
What a good report looks like
One page. Four numbers with last month beside them. A short plain English note about what changed and what is being done next. If a month went badly, it says so and explains why.
If your current report needs a glossary, or runs to forty pages, or never once mentions the telephone, you are not being told whether it worked. You are being shown that work happened, which is a different thing entirely.