How much should you spend on marketing? Start from one customer, not a percentage

Type 'how much should a small business spend on marketing' and you get the same answer everywhere: 2 to 8% of revenue. The SBA's guidance for businesses under $5 million lands at 7 to 8% (via Entrepreneur, Nov 2022). Shopify's 2026 budget guide says 2 to 8% of gross revenue.

None of those numbers tells you what the money buys. A percentage of revenue is a description of what other businesses spend, not a plan for yours. If you have a bit of money set aside and want a first number you can defend, work backward from a customer instead. Here's the rule.

The rule: start from one customer's value

Ask three questions, in this order.

1. What is one new customer worth to you? The profit on one job, one order, or one month of a subscription.

2. How many people who see your marketing become customers? One in ten? One in fifty? Your honest guess, from whatever history you have.

3. So what can you pay to reach them?

Divide the first by the second. That's the most you can pay for one person's attention and still break even. Anything under that is making you money.

That's it. The percentage answers 'what's normal'. This answers 'what can I afford'. Only one of those is your question.

A worked example you can redo on a napkin

Say you run a service business where one customer is worth $400 in profit, and about one in ten of the people who reach your site enquires.

One visit is worth $40 to you: $400 divided by 10. That's your break-even price for a click. Every dollar under $40 is profit waiting.

Now the napkin math for three click prices:

• At $3 a click, ten visits cost you $30 and your one-in-ten rate turns them into one enquiry. That enquiry costs $30 and is worth $400, so about $370 profit per customer. At $3, keep the tap running.
• At $20 a click, ten visits cost $200 for the same one enquiry. Still profitable, but $200 of your $400 is gone before you've covered the work. That's the price where you'd start hunting for a narrower target.
• At $45 a click, the enquiry costs $450. You lose $50 on every customer. Turn it off.

What to put the money on first

So your first budget isn't a percentage of revenue. It's: put a small, capped amount on the narrowest thing that works, one specific search or one specific audience, and check that your cost per enquiry stays under $400. The further under it you land, the harder you push.

This is the same math behind the $12-a-day ad: one ad, one search, one page. The narrow target is what makes a small budget work, not the size of it.

The narrowest thing that works is rarely a big campaign. For most small businesses it's one of:

• A small ad on one specific search people actually type when they need you.
• Fixing the pages that answer the questions customers already ask, so search and AI assistants can find and quote you. This costs time more than money, and it keeps working.
• A steady, consistent presence on the one or two channels where your customers already are.

The two-week test

Notice what's missing: being on every channel. A budget spread across six channels is six rounding errors. Pick the narrowest thing that reaches people ready to buy, put a small slice there, and leave the rest alone until it proves itself.

Whatever you spend, give it two weeks and judge it on one number: enquiries or orders, not clicks, not impressions, not followers. (We've written before about numbers that feel good versus numbers that pay rent.)

• If it pays: keep it, and only then add a little more. Growth is earned by the channel, not granted by the budget.
• If it doesn't: turn it off and try the next narrow thing. You lost two weeks and a small cap, not a quarter.
• If you can't tell: your tracking isn't connected, and that's the first thing the money should fix. 'Not measured' is not zero, and a budget you can't measure is a donation.

What no percentage can promise

Being honest about limits is part of any budget that holds up. No formula, not ours and not the SBA's, guarantees that the money turns into customers. Search engines and platforms decide what they show. Some narrow tests fail. Some months a channel that worked stops working.

What the backward rule gives you isn't a promise. It's a ceiling. You know the most any customer can cost you, so every experiment is affordable by design, and the losers get switched off instead of argued with. That's the real advantage a small budget has over a big one: you can find out fast.

If you'd rather not run it yourself

The budget is the easy half. The work is making the pieces, keeping the pages current and showing up every week, which is usually where owners run out of hours. Nouna is a marketing department for hire: a CMO and eight specialists who plan, write and post daily, from $149 a month, and it never spends or raises an ad budget without your explicit yes. Give it your website and see real finished work on your own business first, free, no card.