Short answer: there is no correct number, but there is a correct method. Work out what a customer is worth to you, decide how many more you want, and spend up to the point where the next customer still costs less than they're worth.

Percentage-of-revenue rules of thumb are common — established businesses often plan a single-digit percentage of revenue, businesses trying to grow fast plan more. They're a useful sanity check, not an answer. Two businesses with identical revenue can justify wildly different budgets depending on margin and customer lifetime value.

Start with what a customer is worth

Before any budget conversation, you need two numbers:

  • Average value of a customer — not one transaction, but everything they spend with you over the time they stay.
  • Your margin on that — what's actually left after cost of delivery.

If a customer is worth $2,000 over two years at 40% margin, you have roughly $800 of room. Spending $200 to acquire one is excellent. Spending $900 is losing money slowly while looking busy.

Most small businesses have never calculated this, which is why marketing budgets get set by gut feel and then abandoned when they feel expensive.

Split the budget by job

A workable way to divide whatever number you land on:

  • Foundations first. Website, search visibility, and basic tracking. This is usually a larger up-front cost and a smaller ongoing one. Skipping it makes everything else less effective.
  • Demand capture. Paid search and SEO — reaching people already looking for what you sell. Highest intent, fastest to prove.
  • Demand creation. Social, content, email — reaching people who don't know they need you yet. Slower, compounding, cheaper over time.

Early on, weight heavily toward foundations and demand capture. Demand creation matters more once the capture channels are saturated.

The mistakes that waste small budgets

  • Spending on traffic before the destination works. Ads pointing at a slow, unclear website burn money at full speed.
  • Spreading too thin. A small budget across five channels does nothing on any of them. One or two channels done properly beats five done partially.
  • Stopping too early. Most channels need a few months to produce a readable signal. Switching every six weeks means never learning anything.
  • Not tracking. If you can't attribute enquiries to a source, you're not budgeting — you're guessing with money.
  • Paying for reporting rather than work. If a large share of your retainer produces a monthly slide deck, that's the agency's overhead, not your marketing.

A sensible starting shape

For a small US business starting properly rather than dabbling:

  1. Fix the website and tracking first — a defined project, not a monthly fee.
  2. Commit to one acquisition channel for at least three months, with a budget you can sustain that whole time.
  3. Build the email list from day one, because it costs little and you own it.
  4. Add channels only once the first one is producing predictably.

A budget you can sustain for six months beats a larger one you abandon in six weeks.

Common questions

Is there a minimum worth spending?

Below a certain point, paid advertising can't gather enough data to optimise and you're better off putting the money into your website and search visibility. If the budget is very tight, spend it on the foundations, which keep working after you stop paying.

Should the agency fee come out of the ad budget?

Keep them separate in your own accounting. Agency fees buy expertise and time; ad spend buys attention. Blending them hides which one is underperforming.

How do I know if I'm overspending?

When your cost to acquire a customer approaches what that customer is worth. That's the ceiling, and it's a hard one.

If you'd like help working out what your numbers actually justify before you commit to anything, book a free strategy call.