ROI and Payback: Is This Worth It?
Two calculations that decide whether a spend was an investment or a donation — and why payback matters more when nobody is funding you.
What this module is for
Be able to judge any spend — a campaign, a contractor, a tool, a trade show — with two numbers you can defend: what it returned, and how long it took to come back.
Work through the sections in order. Each one ends with something to write, and everything you write collects into the worksheet at the foot of the page. Use your own real numbers — an approximate figure you can defend beats a precise one you invented.
Where Aurygine already records a figure, the module points at it rather than asking you to retype it. Where it does not, write it down and close the gap.
Educational content only. Nothing in this track is tax, accounting, legal or investment advice. Use a qualified professional for formal reporting, filings and compliance.
Return, and how long it takes to come back
ROI answers whether it was worth doing. Payback answers whether you can survive doing it.
Return on investment (ROI)
(Gain from investment − cost of investment) ÷ cost of investment × 100
Expressed as a percentage. The gain must be profit, not revenue.
A campaign, measured honestly
- Cost of the campaign: 1,000.
- Gross profit it produced (not revenue): 3,000.
- ROI = (3,000 − 1,000) ÷ 1,000 × 100 = 200%.
Use profit, not top line
If that campaign had produced 3,000 in revenue at a 30% gross margin, the real gain was 900 and the ROI was −10%. Using revenue as the gain is the most common way founders talk themselves into a losing channel.
Payback period
Cost of acquisition ÷ net monthly profit from those customers
Answer in months. Use the profit those specific customers generate, not company-wide profit.
The same spend, in time
- Cost to acquire a cohort: 2,000.
- Net profit from those customers per month: 500.
- Payback = 2,000 ÷ 500 = 4 months.
A shorter payback means less risk and easier bootstrapping: the money returns in time to be spent again. A long payback is a loan you granted yourself, and it has to be funded from somewhere while you wait.
Your numbers
- Net gainProfit produced − cost of the investment.unknown
- ROI(Gain − cost) ÷ cost. The gain must be profit, not revenue.unknown
- Payback periodAcquisition cost ÷ net monthly profit from those customers.unknown
Every figure above is calculated only from what you entered, in your own currency. Nothing is inferred, modelled or benchmarked. Educational worksheet, not financial advice.
Start with: “What it cost, what it returned per month, and how many months that is.”
Reading the result without flattering yourself
The two numbers can disagree. When they do, your cash position decides which one wins.
- High ROI with a long payback can still be dangerous. A 300% return that arrives over eighteen months does not pay next month's invoices.
- Fast payback with modest ROI can be exactly right early. It stabilises cash and lets you keep testing without new capital.
- Negative ROI is not automatically a stop — but it must be a deliberate, time-boxed investment with a written condition for ending it.
- No measurable outcome is a stop. If you cannot attribute the result, you cannot learn from the spend.
Bootstrapped founders should care about payback more than almost anyone, because there is no buffer between the spend and the consequence. When cash is tight, prefer the fast return over the large one, and revisit the large one when the buffer exists.
Before you trust either number
- 01Use the same window for the cost and the outcome.
- 02Count a customer once, in one channel.
- 03Use gross profit or contribution margin as the gain, never revenue.
- 04Include your own hours if they were a real cost of running it.
- 05Record what you could not measure, as unknown rather than zero.
What you concluded
One page you can keep. It saves on this device, and into your company memory when you are signed in.
Take it further
With a company in Aurygine, this worksheet becomes evidence in your Control Tower ledger, tasks on the Workboard, and context Aury reads in CFO mode.
Start your companyEducational content only. Nothing in this track is tax, accounting, legal or investment advice. Use a qualified professional for formal reporting, filings and compliance.
The rest of the track
Four modules that build on each other. Take them in any order; they were written to be read in this one.
- 16 minReading Your Business: Revenue, Profit, and EBITDAThe hierarchy of business numbers, from money invoiced to money kept — and why good revenue can still be a bad business.
- 14 minCustomer Acquisition Is Not Just AdsFive kinds of acquisition, only one of which has a billing account — and how to measure any of them the same way.
- 13 minHow to Read Your Own NumbersTrends, concentration, quality versus quantity, and the habit of looking early enough to still have options.