A marketer brings the owner a report: a lead from channel A costs a third of what it costs from B. The owner is ready to move the budget. But the report says nothing about which of those people paid or how much money was left after their orders were fulfilled. Until advertising is tied to sales and costs, it is too early to propose the move.
The test has 12 situations: customer needs, segments, offers, economics, retention and experiments. The companies and figures in the questions are illustrative. Answer without hints first, then read the explanations for every option, including the ones you did not pick: they show where the reasoning goes off track.
What the test result tells you
Each fully correct answer earns one point. When a question asks for several options, you must select every correct option and no incorrect ones. Partial answers receive no credit. There is no time limit or pass mark.
After finishing, you can retry questions you missed. Your first attempt remains saved, so you can see improvement after reviewing the explanations separately. A full restart replaces the saved answers and first result; the site asks you to confirm this first.
The test is available in Russian. The English page links to the Russian version. Answers are saved in this browser when local storage is available. They do not transfer automatically to another phone, and clearing site data may delete the attempt. If saving is blocked, a warning appears beneath the test.
A score of 12 out of 12 records your answers to these questions. Client work also requires a calculation with new data and an explanation of its limits. Academia does not issue a certificate or award a qualification based on the result.
Calculate customer cost after lead cost
After the test, work through one more example with two channels. Its figures differ from the question in the test. Costs here are ad spend only. Both channels share the same acquisition period and the same window for waiting on payment. Each lead and each new customer is counted once, and repeat purchases do not count as new customers.
| Measure | Channel A | Channel B |
|---|---|---|
| Ad spend | 100,000 ₸ | 150,000 ₸ |
| Leads | 100 | 50 |
| New paying customers | 5 | 10 |
| CPL | 1,000 ₸ | 3,000 ₸ |
| Ad spend per new customer | 20,000 ₸ | 15,000 ₸ |
CPL is spend divided by leads: 100,000 / 100 = 1,000 ₸ for A and 150,000 / 50 = 3,000 ₸ for B. Looking at that row alone, A wins. But only five of A's hundred leads paid, so each customer cost 100,000 / 5 = 20,000 ₸. B comes to 150,000 / 10 = 15,000 ₸. The expensive lead brought the cheaper customer.
From lead cost to customer cost
Channel A
Advertising: 100,000 ₸
100 leads, 5 new paying customers
CPL 1,000 ₸; per customer 20,000 ₸
Channel B
Advertising: 150,000 ₸
50 leads, 10 new paying customers
CPL 3,000 ₸; per customer 15,000 ₸
Only ad spend is counted. A has the cheaper lead and the more expensive new paying customer.
This is not yet full CAC. Full CAC also includes other acquisition costs: the specialist's time, producing the creatives, the managers' time on new leads. These can differ a lot between channels. Until you have those amounts, name the figure for what it is: ad spend per customer. That way the owner does not mistake it for the full cost of a customer.
Compare order contribution
The owner asks, "So B will bring in more money?" Acquisition cost cannot answer that. Suppose customers from A buy a different set of products and leave 30,000 ₸ each after variable fulfilment costs, while a customer from B leaves 12,000 ₸. Variable costs and returns within the chosen window are already in these amounts; advertising and fixed costs are not.
After advertising, A then contributes 5 × 30,000 - 100,000 = 50,000 ₸ and B contributes 10 × 12,000 - 150,000 = -30,000 ₸. On customer cost you would have picked B; on contribution you can see that its first orders did not even pay for the ads. A has 50,000 ₸ left towards fixed costs. That is a long way from net profit: salaries, rent and everything else still come out of it.
The decision changed because you learned more about customer economics. Had customer value been equal, the comparison might have ended differently. Repeat orders can go into a forecast if you state the horizon and what the forecast rests on. They become actual results only when the money arrives.
The marketing P&L helps you give the owner a sharper answer: how much contribution came in, which costs were deducted and what you do not know yet. In that answer, lead volume is an intermediate line, not the bottom line.
Justify the next allocation
A being in the black last period does not mean it will be the same with double the budget. The next customer may cost more, the audience may shift, and sales may not cope with the load. If managers start answering leads a day late, some new people will go to competitors without ever paying.
Before raising the budget, gather data on returns, repeat orders, payback time and how many orders the team can actually fulfil. Five and ten customers are not enough to forecast the next batch with confidence. So write down in advance how much extra spend you are prepared to test and which observation will tell you to continue or stop. Size the test by risk: how much the business can afford to lose if the hypothesis fails, and how many orders it can take on at all.
If the report and the CRM show different customer counts, agree on definitions first and trace the records. Reconciling analytics starts with the question of what each system actually counted. Otherwise the budget moves because of an accounting difference rather than a difference in results.
Analyse your own mistake
Pick a question you got wrong or guessed. Write down which fact in the question you missed, what you relied on instead, and what extra condition would have made your answer reasonable. Then solve a similar problem with different numbers and no options to choose from: that shows whether you understood the calculation or just remembered the right letter.
If you picked A on CPL alone, the missed fact is simple: the share of leads who paid differs between channels. But the rule "take the lower CAC" breaks too: with contributions of 30,000 and 12,000 ₸, A comes out ahead. A good review names the data the decision depends on and lets someone repeat the calculation.
Exercise on your own project
Take two lead sources from your project over comparable periods. If you do not have a working project, use the figures above and build the table the way you would hand it to a future client.
0 of 5 done
A colleague should be able to recalculate your finished table without you explaining it out loud. If one source brought its leads in later, give them the same time to pay before you compare. If variable costs are unknown, take the calculation as far as customer cost and ask the accountant for the missing figures. A marked gap beats invented profitability: the client can see right away what data they need to bring.
For the lesson's example, the justified conclusion is more cautious than "move the whole budget". B's first orders do not cover its ads, A is positive before fixed costs, and the next allocation is worth testing on a limited amount. Your own table may lead to a different conclusion, but it should follow from your definitions, amounts and observations.