Calculating true customer acquisition cost

Why travel CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → is unusually hard to calculate

In most industries, CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → is simple: marketing spend divided by new customers acquired. In travel and hospitality, three structural features complicate this.

1. Commission is a hidden acquisition cost. When a guest books through an OTA, the hotel doesn't pay upfront ad spend, it pays a commission on the booking value after the stay, typically 15 to 25% for OTAs like Booking.com or Expedia (industry estimate, varies by market and contract). That commission is CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition →, even though no "campaign" was run.

2. Metasearch adds a bidding layer on top. Metasearch engines (Google Hotel Ads, Trivago, Tripadvisor) let hotels bid for placement, then charge either cost-per-click or a commission on resulting bookings. A property might pay Google Hotel Ads directly AND still lose that click to an OTA retargetingretargetingShowing ads to users who have previously visited your site or interacted with your brand, to bring them back and drive conversion.View full definition → the same user later.

3. Attribution windows distort channel comparisons. A paid social ad might get "last-click" credit for a booking that a guest actually discovered via organic search three weeks earlier. Instagram often looks artificially cheap because it captures demand created elsewhere.

The result: comparing a $18 Instagram CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → to a $340 OTA CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → is comparing two different things measured two different ways.

Building the blended CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → formula

The fix is a blended CAC: total acquisition-related cost across all channels, divided by total new guests acquired, computed on a like-for-like basis (same time window, same definition of "cost").

Blended CAC = Total acquisition cost (all channels) / Total new guests acquired (all channels)

But the real work is standardizing what counts as "cost" per channel:

| Channel | What counts as acquisition costacquisition costCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → |

|---|---|

| OTA (Booking.com, Expedia) | Commission paid on completed stay (15 to 25% of booking value, estimate) |

| Metasearch (Google Hotel Ads, Trivago) | CPCCPCCost Per Click (CPC) is the average amount you pay each time someone clicks your ad. It is a core pricing metric for paid search and social advertising.View full definition → spend or commission, plus platform fees |

| Paid social (Instagram, Meta Ads) | Ad spend + agency/creative production cost, amortized |

| Direct/organic (brand site, SEOSEOSearch Engine Optimization: the practice of improving your pages' natural (unpaid) rankings in search engine results pages to attract more organic traffic.View full definition →) | CRMCRMCustomer Relationship Management: software and strategy to manage and analyse customer interactions throughout their lifecycle.View full definition → and website tooling cost, allocated proportionally |

Worked example: the resort's real numbers

Let's rebuild the Tulum resort's channel comparison properly over one quarter.

Instagram (paid social):

• Ad spend: $9,000
• Bookings attributed (last-click): 500
• Naive CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition →: $9,000 / 500 = $18

But: creative production (photographer, video editor, retouching) for that quarter cost $6,000, and an agency retainer of $4,000 supported the campaign. Fully loaded:

• Total cost: $9,000 + $6,000 + $4,000 = $19,000
• True CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition →: $19,000 / 500 = $38

That's already more than double the naive figure.

OTA channel (Booking.com):

• Bookings: 800
• Average booking value: $600
• Commission rate: 18% (estimate)
• Total commission cost: 800 × $600 × 0.18 = $86,400
• OTA CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition →: $86,400 / 800 = $108

Metasearch (Google Hotel Ads):

• CPCCPCCost Per Click (CPC) is the average amount you pay each time someone clicks your ad. It is a core pricing metric for paid search and social advertising.View full definition → spend: $12,000
• Bookings attributed: 300
• Metasearch CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition →: $12,000 / 300 = $40

Now compare fairly: Instagram at $38, metasearch at $40, OTA at $108. Instagram is no longer wildly cheaper, it's roughly on par with metasearch. The original "$18 vs $340" comparison collapsed once production costs were loaded in and once commission was calculated correctly (the $340 figure in the opening scene likely came from dividing total OTA commission by a small subset of high-value bookings, another common distortion).

The real trap: CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → without LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition → is a vanity number

Here's the deeper problem. Even a correctly calculated CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → tells you nothing about whether a channel is "cheap" unless you pair it with LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition → (Lifetime ValueLifetime ValueLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition →, the total revenue or margin a guest generates over the full relationship, including repeat stays).

OTA guests are typically one-and-done: the OTA owns the customer relationship, retargets them for their *next* trip (possibly to a competitor), and the hotel rarely gets repeat direct bookings from that guest. Direct and social-acquired guests, by contrast, enter the hotel's own CRMCRMCustomer Relationship Management: software and strategy to manage and analyse customer interactions throughout their lifecycle.View full definition → (Customer Relationship ManagementCustomer Relationship ManagementCustomer Relationship Management: software and strategy to manage and analyse customer interactions throughout their lifecycle.View full definition → system) and can be remarketed to for future stays at near-zero incremental cost.

A simplified LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition →:CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → comparison for our resort:

• OTA guest: CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → $108, average repeat stays over 2 years: 0.1 (estimate, low OTA loyalty), LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition → roughly $660 → LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition →:CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → ≈ 6:1
• Instagram-acquired guest: CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → $38, average repeat stays over 2 years: 0.6 (estimate, higher for direct-relationship guests), LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition → roughly $960 → LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition →: ≈ 25:1

Suddenly Instagram isn't just "not more expensive," it's the far better investment once repeat behavior is included. But this only becomes visible once CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → is calculated honestly and matched to LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition → over a multi-year window, not a single-stay lens.

A commonly cited healthy benchmark across subscription and consumer businesses is an LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition →:CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → ratio of roughly 3:1 as a minimum, with 5:1 or higher considered strong (estimate, general marketing benchmark, not travel-specific). Travel brands with strong direct-booking loyalty programs, like Marriott Bonvoy or Hilton Honors, are built explicitly to push this ratio higher by maximizing repeat stays from acquired guests. See HBS Online's primer on CAC and LTV for the general framework.

A simple spreadsheet structure to run this yourself

Channel        | Spend/Commission | Loaded Costs | Bookings | True CAC | Avg LTV | LTV:CAC
Instagram      | 9000             | 10000        | 500      | =SUM(B,C)/D | 960  | =F/E
Metasearch     | 12000            | 0            | 300      | =B/D        | 720  | =F/E
OTA (Booking)  | 86400            | 0            | 800      | =B/D        | 660  | =F/E
Direct/organic | 4000 (tooling)   | 15000 (SEO)  | 400      | =SUM(B,C)/D | 1100 | =F/E

Run this quarterly, per property, per channel. The columns matter more than the tool: always separate raw spend from loaded costs, and always attach an LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition → window (12 to 24 months minimum for hospitality, given trip cycles).

Key Takeaways

• Never compare raw last-click CAC across channels. Load in commission (OTAs), creative/agency costs (paid social), and platform fees (metasearch) before comparing anything.
• OTA commission is CAC, typically 15 to 25% of booking value (estimate), even though it feels like a "cost of sale" rather than a marketing cost.
• Cheap CAC channels can be the worst investment if they generate low-LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition →, one-time guests. Always pair CACCACCustomer Acquisition Cost (CAC) is the total sales and marketing spend divided by the number of new customers gained in a period. It measures how efficiently you grow.View full definition → with LTVLTVLifetime Value: the total revenue (or profit) a customer generates throughout their entire relationship with your business.View full definition → over a 12 to 24 month window before reallocating budget.
• Direct and social-acquired guests usually have higher LTV because the hotel, not an intermediary, owns the CRMCRMCustomer Relationship Management: software and strategy to manage and analyse customer interactions throughout their lifecycle.View full definition → relationship and can remarket at low cost.
• Target LTV:CAC of at least 3:1, with 5:1+ considered strong (general marketing estimate), and recalculate quarterly since seasonality and commission rates shift the picture.