How to allocate shared sales costs across acquisition channels

01

Choose the cost pool and driver

Define the period and channels first. List salary, benefits and relevant tools for staff who acquire new customers. Remove the portion spent on existing customer service or other work if it is outside the calculation. Avoid counting an agency invoice or tool subscription in both a direct channel cost and the shared pool.

An allocation driver is the basis used to divide a shared amount. Logged acquisition hours by source can be useful if staff record them consistently. If reliable time data is unavailable, use a documented estimate, or report media-only costs until the team can collect better information. Lead count is easier to obtain but can be misleading when some leads require much more work.

State whether the comparison is a period measure or a cohort measure. Spending in a month and customers won that month do not necessarily belong to the same buying cycle. Use a fixed outcome window when tracking a cohort and keep open opportunities visible.

02

Make the allocation

Suppose a team has $8,000 of shared acquisition labor in a month. Its reviewed time records show 30 hours on search leads and 10 hours on referrals, with no other acquisition channels in scope. Allocate 75% to search ($6,000) and 25% to referrals ($2,000). If search also has $4,000 of directly assigned media cost, its stated total is $10,000.

If 20 new customers are credited to search under the chosen attribution rule in that same period, period CAC is $10,000 divided by 20, or $500. Label it a period estimate: those customers may have first inquired earlier. Confirm the channel allocations sum to the original $8,000, and count each new customer once under the stated credit rule.

If no customers are credited to a channel, report its allocated cost and zero customers. Its cost per customer is undefined. Missing source should be a visible category, not silently assigned to the largest channel.

03

Check whether the decision changes

Repeat the comparison using another defensible driver, such as reviewed workload estimates, and show both results. If the channel ranking changes, the decision depends on the assumption. Collect better time data before moving a large budget. Check whether a few unusually complex deals or employee absences made the period unrepresentative.

Keep a worksheet with cost, owner, period, acquisition share, driver, channel allocation and source. Review it with the sales team each period. Compare the allocated acquisition cost with customer contribution and the timing of the buying cycle, not only the cheapest reported number.

04

Check allocation coverage

If the shared cost pool is $8,000, the amounts allocated to all channels plus an explicit unknown-source bucket must add back to $8,000. Where only 80% of acquisition time has a known channel, leave the remaining 20% visible rather than redistributing it silently. Record an alternative allocation separately if management needs a scenario.