B2B SaaS: Pipeline-to-Spend from 0.8x to 6.0:1 - CAC Payback from 13.6 to 7.1 Months
CPL went up. Cost per SAL went up. CAC fell by 40%. The board stopped asking whether paid was viable.
The three highlighted rows are the metrics that determine whether a paid channel is economically viable.
| Metric | Before | After | Change |
|---|---|---|---|
| Monthly spend | £120,000 | £120,000 | Same |
| Cost per MQL | £340 | £1,500 | Up* |
| MQLs per month | 353 | 80 | Down* |
| MQL to SAL rate | 38% | 62% | +24% pts |
| SALs per month | 134 | 50 | Down* |
| Cost per SAL | £895 | £2,400 | Up* |
| Show rate | 51% | 74% | +23% pts |
| SAL to Opportunity rate | 29% | 44% | +15% pts |
| Opportunities per month | 20 | 16 | Down* |
| Cost per Opportunity | £6,050 | £7,362 | Up* |
| Close rate | 14% | 28% | +14% pts |
| Won deals per month | 2.8 | 4.6 | +64% |
| Overall win rate | 0.8% | 5.6% | +600% |
| CAC | £43,211 | £26,087 | -40% |
| CAC Payback Period | 13.6 months | 7.1 months | -6.5 months |
| ACV | £38,000 | £44,000 | +16% |
| LTV (3-year capped) | £114,000 | £132,000 | +16% |
| LTV:CAC | 2.6:1 | 5.1:1 | +96% |
| Annual churn | 19% | 13% | Monitored |
| Pipeline:spend (6 months) | 0.8:1 | 6.0:1 | +650% |
* Rows marked Up or Down moved intentionally. CPL, Cost per SAL, and Cost per Opp increased because the funnel now buys fewer, better-qualified leads at the same spend. CAC fell 40% because the close rate doubled.
% pts = percentage point change in the rate itself. Example: close rate moving from 14% to 28% is a +14% pt improvement, or a +100% relative increase.
A mid-market B2B SaaS company spending £120,000 per month had a CPL of £340, 353 MQLs per month, and an overall win rate of 0.8% from MQL to closed deal - one customer for every 125 leads. The LTV:CAC of 2.6:1 sat below the minimum viable 3:1 threshold. CAC payback at 13.6 months was tying up working capital for over a year per acquisition. Before touching a single campaign, we mapped all six business fundamentals, identified that the bid strategy had never seen a closed-won record, and rebuilt the system in sequence: fundamentals first, paid media system second, funnel third. CPL went from £340 to £1,500 and cost per SAL rose from £895 to £2,400 - both intentional. Won deals per month went from 2.8 to 4.6. CAC fell 40% from £43,211 to £26,087. LTV:CAC went from 2.6:1 to 5.1:1. CAC payback fell from 13.6 months to 7.1 months. Pipeline:spend went from 0.8:1 to 6.0:1.
Before changing anything, we pulled 14 months of closed-won CRM data and mapped every converted customer by job title, company size, search query, and time-to-close. Three persona clusters emerged with different conversion economics: finance leaders (fastest close, highest ACV), operations leads (longer cycle, lower churn), and IT decision-makers (proof-dependent, most mid-funnel content needed before booking). That data set every subsequent decision.
Show rate at 51% was the fastest fix with zero media spend dependency. A four-touch pre-call confirmation sequence - confirmation email with agenda, 24-hour case study matched to the prospect's role, two-hour SMS from the closer, 30-minute final nudge - brought it from 51% to 74% within 30 days. MQL-to-SAL at 38% was the second constraint, fixed with a qualifying form that filtered by ICP before any lead reached the sales calendar. Churn at 19% was flagged to the CMO as a retention problem outside paid scope but factored into every LTV calculation.
The CPL target was deliberately raised. Fewer, better-qualified MQLs were the goal, not cheaper volume. Each persona got dedicated Google Search campaigns on exact and phrase match only. LinkedIn ran a three-stage account-warming sequence: problem-framing content to cold ICP accounts with no conversion ask, anonymised proof content to engaged accounts, and a direct demo CTA only to accounts with 3 or more prior touchpoints. Five offer angles were tested per persona at 200 qualifying form completions each, with budget moving only to the variant with the lowest cost per ICP-confirmed SAL.
A two-step qualifying form replaced every generic contact form. Sub-ICP submissions routed to a five-email nurture sequence, not the CRM. Server-side CAPI was configured and 14 months of closed-won records were imported into Google Ads as an offline conversion event - so the algorithm trained on the job titles, company sizes, and queries that became signed and retained customers. HubSpot was configured to report cost per SAL, cost per opportunity, show rate, close rate, CAC, and LTV:CAC weekly to both marketing and sales.
£4.3M in attributed pipeline over 6 months from £720,000 in total spend - a 6.0:1 pipeline-to-spend ratio, up from 0.8:1. 98 qualified opportunities created. 28 won deals at an average ACV of £44,000. Paid pipeline contribution grew from 9% to 41% of total new business.
Overall win rate from MQL to Won improved from 0.8% to 5.6%. Won deals per month from 2.8 to 4.6. CAC reduced from £43,211 to £26,087 - a 40% reduction on the same budget. CAC payback fell from 13.6 months to 7.1 months. LTV:CAC improved from 2.6:1 to 5.1:1. Cost per MQL increased from £340 to £1,500 and cost per SAL from £895 to £2,400. Both were intentional.
The board stopped asking whether paid was viable at month five. The sales director requested a budget increase at month four - the first in two years. The weekly complaint call about lead quality stopped at week six. Paid became the fastest-closing source in the CRM at an average of 11 days from SAL to booked opportunity, versus 34 days for outbound-sourced leads.
The first question was not about budget or channels. It was what our LTV:CAC and CAC payback looked like. I realised we had never calculated either before that conversation.
The constraint was that 353 MQLs per month at a 0.8% overall win rate is not a paid media success - it is an expensive prospecting exercise. The bid strategy had been optimising toward cheap form fills for 14 months while the business needed it to find buyers. One number clarifies the apparent contradiction in the after-state metrics: cost per SAL and cost per Opp both rise, while CAC falls. This is not inconsistent. With fewer SALs and opportunities at the same spend, the cost per unit goes up. But because the close rate doubles from 14% to 28%, each opportunity is twice as likely to produce a customer, so the cost per won deal falls sharply. The only metric that tells you whether the paid channel is economically viable is CAC relative to LTV. Everything else is an intermediate signal.
