The slide is up. Marketing leadership, one line, and the debate has already collapsed into a monthly number. A full-time CMO package on one side. A fractional operator on the other. Someone says the words "we should just get a real CMO in here," and the room nods, because that sounds like the decision a Series B company makes.
It is the wrong debate. The Series B marketing leadership decision turns on one question: is your growth motion proven and repeatable, or are you still discovering it. If one ideal customer profile, one path from source to closed won, and a conversion rate that has held for two or three quarters, you are hiring someone to scale a known machine. If not, you are hiring someone to find the machine, and that is a different job with a different risk profile.
This piece gives you three things. A test for which situation you are actually in. The speed and risk math boards tend to skip. And the questions to put on the table at your next meeting.
Comparing a salary to a monthly fee assumes both options buy the same thing. They do not. A full-time CMO hire is a bet that you already know which motion you are scaling. A fractional operator buys the diagnosis first, then builds from what the evidence says, not from what the job description assumed.
The commitment difference is measurable. A fractional engagement starts in weeks and is scoped to six to twelve months at 40 to 70 hours a month, at a market rate of $8,000 to $25,000 a month. A full-time hire adds salary, bonus, equity, a search fee and a quarter of ramp before the first plan ships. That is not an argument about savings. It is an argument about how much you are locking in before you know what you are scaling.
Read it as optionality. At Series B, the expensive mistake is not paying for senior marketing leadership. It is committing a year of budget, a planning cycle, and a team structure to a motion that turns out not to be the one that repeats. Buy the diagnosis on a 30-day commitment. Buy the permanent hire once the motion is proven and you can write the spec with confidence.
A proven growth motion has four parts: one primary ICP, one repeatable path from lead source to closed won, a conversion rate that holds within a few points across two or three consecutive quarters, and a forecast that lands inside a defensible range. If all four are true, you are scaling a known machine and a full-time CMO is the right hire. If any one is missing, you are still running discovery, and the first job is diagnosis.
Four evidence checks settle it:
Four criteria decide this: ARR band and growth rate, where pipeline comes from, how many ICPs are in play, and how much runway you have before Series C metrics are due. Score them honestly and the answer usually picks itself.
Proven motion, one ICP, system-led pipeline, and 24 months of runway point to full-time. Anything else points to fractional first.
The full-time path costs you a planning cycle before it costs you a salary. A CMO search typically runs three to six months to signed offer, another one to three months of notice, then a 90-day ramp before the first real strategy lands. Add it up and you are nine to twelve months from board decision to a marketing plan you can act on. A fractional operator starts inside weeks and is running diagnosis in the first 30 days.
Set that against the McKinsey timeline cited above. Boards allow nine months for vision and 14 months to build a team. If your Series C metrics are due in 18, the search itself eats most of the window.
Then there is the mis-hire. National executive turnover data puts first-18-month failure in the range of one in three. The cost is not the severance. It is a marketing team that churns behind a departing leader, a planning cycle spent on a strategy nobody now owns, a budget rebuilt mid-year, and a second search starting from zero with less runway than the first.
The question is not who writes the strategy. It is whether the engagement leaves behind an operating system and a team that runs it, or a document you still have to execute yourself.
A fractional CMO owns the number from the first week. The work runs in order: diagnose the motion, fix what is broken in the funnel, build the demand engine, then instrument it so the pipeline forecast holds within a defensible range quarter to quarter. Somewhere between month four and month nine, when the motion is proven and the reporting is real, the same operator writes the spec for your permanent CMO. That spec is specific: the segments in play, the channel mix that works, the team structure, the compensation logic, and the first 90 days the new leader inherits. Then they hand off and stay available through the transition.
Specialist execution sits with vetted partners inside the engagement. Media buying, creative production, web build. You get one accountable leader, not a stack of vendors reporting to you.
Hire a full-time CMO when the job has become daily ownership of a proven motion rather than discovery of one. Four or five signals tell you that moment has arrived.
Marketing spend is running across four or more channels at a level that needs someone watching it every day, not every week. The marketing team is large enough that management is the job, roughly six or more people with functional leads under them. Brand and category position have moved onto the board agenda as an investment, not a line item. Your investors expect a named CMO on the Series C deck, and they have said so. And the motion is proven in one segment with two or more segments queued for expansion.
If all five are true, run the search now. If two or three are true, run fractional and convert. Put the operator in place, let them prove the motion over two or three quarters, and let the evidence they build write the job description you hire against.
Four questions settle this faster than another cost comparison. Which single motion produced most of last quarter's closed won, and does that path hold for two or three quarters running? How much of pipeline still comes from the founder's relationships rather than the system? How many ICPs are we funding at once, and which one would we cut? And if we start a CMO search this month, what is our plan for the two or three quarters before that person is productive?
We work the same way. The 100-Day Accelerator runs Plan, Activate and Accelerate as overlapping phases, with measurable results in 100 days and a Sustain phase after that, so you get executive revenue leadership without the full-time overhead while the motion is still being proven. Every engagement carries named exit criteria: the motion documented, the demand engine operating, the team in place, and the spec written for the permanent CMO. Specialist execution sits with vetted partners inside the engagement.
This week, write one page: the growth motion you believe is repeatable and the evidence behind it. Take that page to the board.