Customer Acquisition Cost at the Campaign Level
Go beyond blended CAC to see what you are paying to acquire a new customer from each specific campaign — and use the data to optimise your marketing budget allocation.
Why blended CAC misleads
Blended CAC (total marketing spend ÷ total new customers) averages across all campaigns and channels. It tells you what you are paying on average but hides enormous variation — a campaign with a £15 CAC and a campaign with a £120 CAC both contribute to a blended figure of maybe £45.
If you scale based on blended CAC, you may be scaling the expensive campaigns along with the efficient ones. Campaign-level CAC tells you which campaigns to pour budget into and which to pause.
AskBiz calculates CAC at the campaign level for all connected ad platforms.
How campaign-level CAC is calculated
Campaign CAC = Campaign Spend ÷ New Customers Acquired via that Campaign
AskBiz identifies 'new customers' as buyers making their first-ever purchase from your store. Returning customers are excluded from the new customer count, so retargeting campaigns (which primarily reach existing customers) do not get credit for 'acquiring' them.
To view campaign-level CAC:
1. Go to Marketing → Paid Ads → CAC by Campaign
2. Filter by platform (Google, Meta, TikTok) or view all
3. Sort by CAC to rank from most to least efficient
The view also shows whether the campaign is primarily acquiring new customers (high new customer %) or serving existing ones (low new customer %) — the right comparison benchmark differs for each.
Setting your target CAC
Your target CAC is derived from your LTV and target LTV:CAC ratio.
Target CAC = 12-month LTV ÷ Target LTV:CAC ratio
Example:
- 12-month customer LTV: £180
- Target LTV:CAC ratio: 3:1
- Target CAC: £180 ÷ 3 = £60
Any campaign with a CAC below £60 is above target. Any campaign with a CAC above £60 is below target. Pause campaigns above target; scale campaigns significantly below target.
Enter your target CAC in Marketing → Settings → Target CAC and AskBiz will highlight campaigns above and below target automatically.
Understanding CAC trends over time
CAC tends to increase as you scale a campaign — you exhaust the most efficient audiences first, then expand into less efficient ones. This is normal and does not necessarily mean a campaign is failing.
AskBiz shows CAC trend over time for each campaign — weekly for the last 12 weeks. Look for:
- Gradually increasing CAC: normal scaling behaviour — reassess when CAC approaches your target ceiling
- Sudden CAC spike: creative fatigue, audience saturation, or a competitor entering the auction — investigate immediately
- Declining CAC: campaign is improving as the algorithm optimises — good sign, consider scaling
Set a CAC alert in AskBiz to notify you when a campaign's weekly CAC exceeds your target for two consecutive weeks.