Allocation pattern · B2B SaaS

Series A SaaS: Agency Split Spend Evenly Across 3 Platforms. CAC Was Unattributable.

A $3M ARR Series A B2B SaaS came in 9 months into a performance agency retainer. $30K ACV, sales-led, $18K monthly to the agency plus $40K monthly in media spend. The agency had recommended an even-thirds split across Google search, Meta, and LinkedIn at month 1.

Nine months later, blended CAC was $4,200 with no channel-level attribution that the founder trusted. The agency dashboard reported CPCs trending in the right direction. The board was asking which channel was producing the deals.

The diagnosis (3 sentences)

The even-thirds split was the agency’s defensible default, not a strategic decision derived from the company’s sales motion. Strategy and execution had collapsed into one provider, so the strategy reflected the provider’s billable scope, not the company’s optimal allocation. Nine months of execution had compounded the wrong allocation rather than corrected it.

The allocation move

  • Audit channel-level CAC across all three channels using closed-won deal data from the CRM, not platform-reported conversions. Six weeks of clean attribution work.
  • Reallocate based on what the math showed: 55 percent intent search (Google), 25 percent LinkedIn (Conversation Ads + Document Ads to in-market segments), 15 percent retargeting, 5 percent paused on Meta for a 90-day pause-and-evaluate window.
  • Keep the agency on for execution inside the new framework. The agency is competent at running ads. The conflict of interest only existed in the strategy phase. With strategy decided, the agency operates more focused, not less.
  • Set explicit pause criteria: any channel that fails to hit a 18-month CAC payback by week 12 of the new mix gets paused, not optimized further. Decision rule pre-committed in writing.
  • Set up the weekly KPI review with channel-level numbers the founder can defend to the board. Blended CAC was always going to be the headline. Channel CAC by source is the actionable layer underneath.

When this applies. When it does not.

Applies: Series A B2B SaaS that hired a performance agency on a $10K to $20K monthly retainer in the first 60 days post-close. Channels are split across 3+ platforms in roughly equal thirds. CAC numbers are not channel-attributed with confidence. The agency strategy and execution roles collapsed at the start.

Does not apply: Companies where the channel mix was decided outside the agency before execution began. Or Series B+ companies where the mix has been validated across multiple cohorts and the agency is operating inside a confirmed framework.

A founder line, anonymized

“I assumed the agency was running the strategy. They were running the execution of a strategy that came from their account-rep coverage. Those are two different things. The audit reallocated 60 percent of my spend in 30 days. The agency ran the new mix and got better numbers, faster, than they had in 9 months.”

For the structural conflict between agency strategy and agency execution, and the clean sequence that fixes it, see Fractional CMO vs Paid Media Strategist vs Agency: A Decision Tree for Funded Founders. The decision tree starts with separating the allocation call from the execution call.

Book the 10-Day Allocation Audit.