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Which lead source wins the most instructions? Here's how to measure it
8 min readUpdated
Counting leads will not show you which lead source wins the most sales instructions. You record a fixed, specific source for every lead and carry it through to the signed sales instruction and the commission. Only once at least 70% of your leads have a reliable source do the figures by source tell you anything about what to do.
Why counting leads is not enough
A source with many leads is not automatically a source that delivers much. A valuation-check widget can generate hundreds of requests a quarter, of which a small share sell, while a handful of personal referrals in the same quarter can produce more sales instructions.
The difference is money. In 2025 a selling agent cost €5,800 on average, at an average commission of 1.16% (Krib, analysis of 23,000 quotes). A single sales instruction is therefore worth thousands of euros. Ten leads more or fewer says little. Two sales instructions more or fewer per branch says a lot.
To get from leads to sales instructions, you record seven things. The first three are hygiene, the fourth makes the difference, and the last three turn a report into advice.
| # | What you record | What goes wrong without it |
|---|---|---|
| 1 | Source completeness | With 30% unknown, every conclusion is a guess |
| 2 | Source detail | "Website" is not advice; you cannot direct budget to something without a name |
| 3 | Identity across channels | One person counts three times and the sales instruction is split across three sources |
| 4 | The chain through to commission | Sources with many leads and few sales instructions look good |
| 5 | Timing and lead time | Slow sources appear not to work |
| 6 | Cost per source | You can rank, but not choose |
| 7 | Attribution model | The source that started the relationship gets no credit |
Start with source completeness
The first measurement is what percentage of your leads have a reliable source. Take last quarter's leads and count how often the source field is empty, set to "other", or holds something nobody can trace any more.
Our rule of thumb: if that percentage is below 70%, cleaning up source tracking is your first project, not the report. A report built on a source that is missing for three in ten leads is a chart wrapped around a gut feeling.
Record the source at the moment the lead comes in, automatically wherever possible. A form knows which page it comes from. A source that a member of staff fills in by hand later is the source most often left blank.
Make the source specific enough
A source is only useful if you can base a decision on it. "Website" is too broad. "Valuation on the homepage", "form on the sales page" and "Facebook campaign Alkmaar September" are names you can move budget or attention towards.
Work with two levels: a fixed list of main sources that you rarely change, and beneath it a sub-source or campaign. That keeps quarters comparable while still showing which campaign worked.
| Field | Example | Why |
|---|---|---|
| Main source | Valuation, Funda, newsletter, viewing, referral | Comparable across quarters |
| Sub-source or campaign | Homepage widget, spring campaign | Where you direct budget |
| Date of first contact | 12 March 2026 | Basis for lead time |
| Branch | North branch | Management by branch |
| Agent | The agent handling the file | Management by agent |
| Status | Lead, appointment, sales instruction, lost | Makes the chain visible |
| Date of sales instruction | 4 November 2026 | To calculate lead time |
| Commission | The invoiced amount | What the source actually delivered |
Recognise the same person across channels
Someone who requests a valuation in March, opens a newsletter in June and calls in September is one person, not three leads. Count them three times and you split the sales instruction across three sources, and no figure adds up any more.
Link contact moments to one person by email address, phone number and home address. This is the hardest thing to fix after the fact, so agree in advance who merges duplicate contacts and when.
Follow the chain through to commission
The figure that counts is not the number of leads per source but the commission per source. For that, the source of the first lead has to still be on record at the moment the sales instruction is signed and the invoice is sent.
This is the difficult part. The agency software knows the sales instruction, but usually not where it came from. A lead tool knows the source, but does not see the sales instruction. Realworks has no API for the sales instruction or the commission, so you make that link yourself, with a fixed field or a fixed procedure at signing.
Allow for the lead time
A valuation is orientation. Between that request and a signed sales instruction there are sometimes weeks, sometimes more than a year. If you count by quarter, you see many leads and no sales instructions in the quarter of the request, and write the source off.
So look in cohorts: group leads by the month in which they came in and track, per group, how many have signed after 3, 6 and 12 months. How that works, with a worked example, is covered in from valuation to sales instruction.
Set the costs against the return
Without costs you can rank sources, but not choose between them. Note for each source, each quarter, what it cost: subscriptions, advertising budget, and the hours your team spends on it. Divide that by the number of sales instructions and you have the cost per sales instruction, which you set against the commission per sales instruction.
An example of a source whose costs have just gone up: the new Funda packages. A spreadsheet with one row per source per quarter is enough. The difficulty is not the arithmetic but keeping it up consistently.
Choose how you attribute a sales instruction
A sales instruction that came in through three contact moments cannot simply be attributed to one source. If you count only the last contact, the source that started the relationship gets no credit, even if that was the valuation a year earlier.
You do not need a complicated model. Show first and last contact side by side. Where the two differ sharply, you see which sources start relationships and which close them.
What you put on the table each quarter
With these seven layers in order, you answer one question each quarter: which source produced which sales instruction, at which branch, and at what cost. How to build that by branch and by agent is covered in the quarterly report for a multi-branch agency.
KeyVue records the source of every lead and reports conversion by source, branch and agent, with Realworks as the foundation. Appointments from Realworks automatically become leads, so what comes in by phone or at the counter gets a source too, and for every lead that drops out you record the reason. See how it works on the product page.
Frequently asked questions
You measure it by recording a specific source for every lead and carrying that source through to the signed sales instruction and the invoiced commission. Then count sales instructions and commission per source instead of leads, and look in cohorts, because a valuation request sometimes only signs after a year.
As a rule of thumb, at least 70%. If fewer than 70% of your leads have a reliable source, every conclusion by source is a guess and cleaning up source tracking is your first project. Measure that percentage by going through the source field of last quarter's leads.
Show both side by side. If you count only the last contact, the source that started the relationship gets no credit, for example a valuation from months earlier. First and last contact together show which sources start relationships and which close them, without needing a complicated attribution model.
About €5,800 on average. That is what a selling agent cost on average in 2025, at an average commission of 1.16%, according to an analysis of 23,000 quotes by Krib. The average NVM (the largest Dutch association of estate agents) transaction price of €506,000 in the second quarter of 2026 gives a comparable amount. Your own rate and region determine the actual amount.