The 70/20/10 rule for marketing spend, audited.

The 70/20/10 rule says spend 70% of your marketing budget on what works, 20% on what's promising, and 10% on experiments. It's a reasonable default. It is not a law, and most small businesses apply it before they have the data to know what their 70% even is.

I've allocated budgets for owner-operated firms where the "proven" channel was a referral network nobody had ever measured, and the "experiment" was the only thing actually producing tracked leads. The rule survives the audit about half the time. The other half, it hides a problem. This post walks through how to pressure-test the split against your own numbers instead of adopting it on faith.

What does the 70/20/10 rule actually mean?

The 70/20/10 rule is a way to divide marketing spend across three risk tiers: proven, promising, and unproven. Seventy percent goes to channels and campaigns with a known return. Twenty percent goes to things that show early signal but aren't confirmed. Ten percent goes to pure bets — new channels, new messages, new audiences you haven't touched.

The logic is sound. You protect the core of your business while leaving room to find the next thing before the current thing stops working. A firm that pours 100% into one channel is one algorithm change away from a bad quarter. A firm that spends everything on experiments never builds a predictable pipeline.

The trouble is the word "proven." Most SMEs I audit cannot name their proven channel with a dollar figure attached. They have a feeling. They think Google Ads works because the phone rings. They think the networking group pays off because they got two clients from it once. Those are hunches, not measurements. And you cannot allocate 70% of a budget to a hunch and call it discipline.

How do you find your real 70%?

You find your real 70% by tracing closed revenue back to its source, one client at a time. Not leads. Not clicks. Closed, paid, revenue-producing clients over the last 12 months.

Start with a simple spreadsheet. One row per client who paid you in the last year. Columns for revenue, the channel they came from, and the cost of that channel over the same period. For a San Diego dental practice, that might be: a patient worth $4,200 in lifetime value, came from Google search, acquired against $900 a month in SEO work. For a personal-injury firm, it might be a case worth $18,000 in fees, came from a referral, acquired against $0 in direct spend.

Most owners discover two things when they do this. First, the channel they thought was their 70% is often their 30%. Second, a channel they were treating as an experiment is quietly carrying the business. I audited a firm that was spending $8,000 a month on paid search and 90 minutes a quarter on their Google Business Profile. The paid search produced tracked leads at a cost that erased the margin. The Business Profile produced the firm's three biggest cases that year, for free.

Until you've done this trace, the 70/20/10 split is decoration. You're dividing a budget across tiers you haven't defined. The audit comes first. The allocation comes after. This is the same order we follow in our method — Discover, then Audit, then Position — because you cannot position spend you haven't measured.

When does the rule break for small businesses?

The rule breaks when your budget is too small to make 10% meaningful. Ten percent of a $2,000 monthly budget is $200. You cannot run a real experiment on $200 a month. You'll get noise, not signal, and you'll kill the test before it tells you anything.

For a lot of SMEs, the honest split early on is closer to 90/10/0. Put 90% into the one or two channels you can measure. Put 10% into improving them — better landing pages, better tracking, better follow-up. Skip the experiment tier entirely until you have a proven base worth protecting. There's nothing to hedge against yet.

The rule also breaks when your "proven" channel has no ceiling you've hit. If Google search is bringing you clients and you're nowhere near the top of the results for your core terms, the smart move is to over-invest in that channel, not diversify away from it. Spending 20% on a promising new channel when your proven one still has room is a mistake. You're funding exploration before you've finished mining the vein you already found.

The third failure mode is treating the percentages as permanent. The split should move as your data moves. A channel that was an experiment in January can be your 70% by June. If your allocation hasn't changed in a year, you're not running a system. You're running a habit.

How should a service business weight the split?

A service business should weight the split toward whatever produces its highest-value clients, even when that channel is unglamorous. For professional services, that's often search and reputation, not paid social or clever campaigns.

Here's a working split I've used for owner-operated firms with a modest budget and a clear service offer:

1. 55–65% to search visibility. This is organic search, your Google Business Profile, and the pages on your site that answer the questions your clients type before they call. For a law firm, a dental practice, or an accountant, this is where high-intent clients come from. People search the problem by name. You want to be the answer.
2. 20–25% to conversion and follow-up. Faster response times, a booking system that works, a site that loads in under a second, review requests after every job. This is the 20% tier, and for most SMEs it returns more than any new channel because it fixes leaks in the pipeline you already have.
3. 10–15% to one experiment at a time. One. Not four. Pick a single new channel or message, fund it enough to get a real read, and give it a fixed window — say, 90 days. At the end, it either joins the 70% or it dies. No zombie campaigns.

The mistake I see most is firms running the experiment tier as a graveyard of half-funded ideas. A little paid social, a little email, a little of whatever a conference speaker recommended. None of it gets enough budget to prove itself, so none of it ever graduates or gets cut. Concentration beats diversification when you're small. One experiment, fully funded, teaches you something. Five experiments, starved, teach you nothing.

When McShanes Solicitors worked through their allocation, the gain didn't come from a new channel. It came from pointing more of the budget at search — the channel already producing their best clients — and tightening the follow-up on the leads it generated. The 70% got bigger and the leaks got smaller. That's the audit doing its job.

Who should own the allocation decision?

The person who owns the allocation decision should be able to tie every dollar to a revenue outcome and adjust the split as the data changes. For most small businesses, that's the owner, until the budget grows past the point where the owner has time to run it properly.

This is the gap a Fractional CMO fills. Not to take the budget off your hands, but to bring the discipline of the audit — the revenue trace, the tiering, the quarterly reallocation — without the cost of a full-time hire. The job is to make the 70/20/10 split mean something, then keep it honest as the numbers move. If you're wondering whether that's a role you need yet, we wrote a plain breakdown in when you actually need a Fractional CMO and when you don't.

What you want to avoid is handing allocation to whoever sells you a channel. An agency that runs paid search will tell you paid search deserves 70%. An agency that runs social will tell you social does. Neither is auditing your revenue. Both are allocating toward their own invoice. The difference between advice tied to your numbers and advice tied to someone's product is the whole game, and we covered it in Fractional CMO vs agency: the difference that matters.

Where this breaks down

The 70/20/10 rule assumes you can measure channel attribution cleanly, and for a lot of service businesses you can't. A referral started with a Google search three months earlier. A new patient saw your sign, then checked your reviews, then called. Attribution for high-consideration services is messy, and anyone who tells you otherwise is selling a dashboard. Treat the split as a guide, trace what you can, and don't pretend to a precision the data doesn't support. The goal is a defensible allocation, not a perfect one.

The rule is a frame, not an answer. Run the audit first. Find your real 70% by following the money to closed clients. Then split what's left with discipline — one experiment, fully funded, on a clock. Foundations first.