Setting a CAC target before the first ad dollar goes out

We won't launch a paid campaign without a target cost per acquisition set in advance, because without one there's no way to know if a campaign is working until the budget is already spent. This sounds obvious and is skipped constantly, usually because setting the number properly requires a harder conversation about unit economics than most teams want to have before they've seen any results at all.

It's a lot easier to launch a campaign on enthusiasm and check the results later than to sit down beforehand and calculate exactly what a business can afford to pay for a new customer. But that avoidance has a real cost: without a number agreed on in advance, every campaign review becomes a subjective argument about whether the results feel good, and subjective arguments are where budgets get cut for the wrong reasons or extended for reasons that don't hold up under scrutiny.

The target CAC has to come from a real number: average order value, repeat purchase rate, or contract length and churn for a subscription business. A target CAC set as "whatever feels reasonable" instead of derived from actual unit economics is a target that can't actually tell you whether a campaign is profitable, only whether it feels busy.

For a subscription business specifically, we push clients to calculate lifetime value using actual churn data from their existing customer base, not an optimistic assumption about future retention. A first-time founder without churn data yet has to estimate conservatively, and we'd rather start conservative and adjust upward than the reverse.

This is usually the first place a founder's optimism gets gently corrected. Early pitches to us often include a lifetime value figure based on the best-case customer who stays for years and refers three friends, rather than the median customer who churns within a few months. We ask for the actual distribution, not just the standout example, since a CAC target built on the best customer rather than the typical one sets every subsequent campaign up to look worse than the plan predicted.

A CAC that exactly equals lifetime value isn't a target, it's a breakeven line, and a business running at breakeven on paid acquisition has no room for the inevitable weeks where costs spike due to competition or seasonality. We typically target a CAC at 60 to 70 percent of estimated lifetime value, leaving real margin.

That margin also funds the learning phase itself. Early weeks on a new campaign are rarely the most efficient ones, and a target with no room built in means the campaign looks like it's failing during exactly the period it's supposed to be finding its footing.

Lifetime value spread over three years is a very different cash position than the same lifetime value realized in the first three months, even at an identical CAC-to-LTV ratio. A business with tight cash flow needs to weight payback period, how long until a given customer's spend covers their own acquisition cost, alongside the ratio itself, since a technically profitable target can still starve a business of cash if the payback window is too long relative to how fast the business needs to reinvest to keep growing.

A single blended CAC target across Google Ads, Meta, and organic-assisted conversions hides which channel is actually doing the work. We set per-channel targets and track them separately, because a channel that looks expensive in isolation might be feeding conversions that show up as "direct" traffic elsewhere, and a blended number would mask that entirely.

Setting per-channel targets also protects against a common mistake: shutting down a channel that's genuinely working because its isolated CAC looks worse than another channel's. A prospecting campaign on a top-of-funnel platform will almost always show a higher CAC in isolation than a retargeting campaign closing people who already know the brand, simply because the two are doing different jobs in the funnel. Judging both against the same blended number consistently punishes the channel doing the harder, earlier work.

Lifetime value assumptions change as a business matures, pricing shifts, or the product mix changes. A CAC target set once at launch and never revisited becomes stale within two quarters for most growing businesses. We put a calendar reminder on this specifically because it's the kind of task that's easy to skip when nothing is visibly broken.

The revisit itself is a short exercise, usually under an hour: pull the actual average order value and repeat purchase rate from the last quarter, recalculate lifetime value, and check whether the existing CAC target still leaves the margin it was originally designed to leave. Most quarters, the number barely moves. Occasionally, a pricing change or a shift in the customer mix moves it meaningfully enough that a campaign judged against the old target would have looked wrong for months.

When a campaign is running above target CAC, the conversation isn't "the campaign isn't working," it's "we're currently at $54 against a $40 target, here's what we're testing to close that gap." A pre-agreed number turns an emotional conversation about disappointing results into a specific, solvable engineering problem, which is a much more productive place for both sides to be.

A subscription client came to us with no CAC target at all, just a general sense that acquisition felt expensive. We calculated lifetime value from their actual churn data, landed on a target of $85, and found their current campaigns were running at $110, comfortably above target rather than in some vague danger zone. That specific gap let us prioritize exactly two fixes, tightening audience targeting and rewriting the landing page's above-the-fold offer, instead of a broad, unfocused overhaul of everything at once.

Without a target, campaign reviews turn into a debate about whether numbers "feel" good, which is a debate nobody wins and every stakeholder answers differently. With a target, the review is a single comparison: are we above or below the number, and by how much. That's the entire point of setting it before spending the first dollar.