Summary

  • Klaviyo generated US$728.6 million of revenue and US$538.0 million of gross profit in the first half of 2026. Its reported gross margin therefore measures service delivery before the disclosed Shopify distribution costs recorded in selling and marketing.
  • The company incurred US$18.0 million of Shopify revenue-share fees in the half, up from US$16.0 million a year earlier. Shopify is defined as a vendor providing marketing and customer-acquisition services, not as a customer, reseller or distributor.
  • A separate warrant mechanism added US$16.2 million to a prepaid marketing asset while US$26.4 million was amortised into marketing expense. The asset fell by US$10.2 million to US$122.6 million, reconciling the two flows at the disclosed level of rounding.
  • The US$18.0 million revenue share plus US$26.4 million of warrant amortisation equals US$44.4 million, or 16.2% of first-half selling and marketing expense. That sum is a known accounting-cost bridge, not a claim that Klaviyo paid US$44.4 million in cash to Shopify during the period.
  • Investors need a partner contribution schedule linking attributed revenue, messaging and infrastructure cost, revenue share, retention and expansion. Dividing the fee by a headline percentage cannot recover Shopify-attributed revenue because the agreement contains more than one payment formula and an undisclosed attribution perimeter.

The cost that gross margin does not see

The income statement invites a clean first reading. For the three months to June, Klaviyo recorded US$370.6 million of revenue, US$101.5 million of cost of revenue and US$269.1 million of gross profit. The resulting 72.6% gross margin was down from 75.7% a year earlier. Klaviyo explained that cost of revenue rose as platform usage increased. Text and WhatsApp volume, cloud infrastructure and outbound-message charges belong naturally in that discussion.

Shopify’s disclosed toll enters later. Klaviyo says the collaboration is a services contract under which Shopify supplies marketing and customer-acquisition services. The company expressly says Shopify is not its customer, reseller or distributor and does not perform services on Klaviyo’s behalf. Fees under the revenue-sharing agreement are therefore recorded in selling and marketing expense.

That treatment does not make the reported gross margin wrong. It defines what the number answers. Gross margin shows the economics of operating and delivering the platform under Klaviyo’s accounting classification. It does not show the contribution left after paying a major ecosystem for attributed customer access. A buyer of the shares who treats gross margin as the full variable economics of a Shopify-sourced customer is asking the line to answer a question it was not designed to answer.

The distinction matters because Klaviyo’s product can be embedded deeply in a merchant’s operating flow while its route to that merchant remains economically shared. Data storage, email, text messages, WhatsApp traffic and service conversations generate delivery costs above gross profit. Attribution and integration with Shopify generate a separately classified marketing charge below it. Both can vary with adoption, but they live in different income-statement neighbourhoods.

Two payment formulas, not one take rate

Klaviyo’s annual filing describes at least two cash-fee mechanisms. For designated Shopify Core merchants whose leads are attributed to Shopify, the Core revenue share is 15% of relevant revenue above a US$1 million threshold. The exact perimeter matters: not every Klaviyo customer is a Shopify merchant, not every Shopify merchant is necessarily within the designated group, and not every dollar is necessarily an attributed lead.

The Shopify Plus integration fee works differently. It is charged monthly for a qualifying Shopify Plus merchant when the covered store has Klaviyo installed at both ends of the month and data activity is present through webhook requests or API calls. Shopify may elect an annual increase subject to a contractual formula. That is closer to a fee on an active installed relationship than a simple percentage of recognised revenue.

The half-year fee was US$18.0 million, compared with US$16.0 million in the first half of 2025. The 12.5% increase was slower than Klaviyo’s 27.2% revenue growth over the same comparison. That difference is worth observing, but it is not yet proof of improving partner economics. Mix between Core and Plus can move. Attribution can move. Threshold effects, installed stores, integration status and annual fee resets can move. Acquired and non-Shopify customers can enlarge the revenue denominator without changing the Shopify fee in the same proportion.

For the same reasons, it would be invalid to divide US$18.0 million by 15% and announce US$120 million of Shopify-attributed revenue. The filing describes an amount above a threshold for one population and a separate integration fee for another. It does not disclose the overlap, the fee split, the number of relevant merchants or the revenue base. An apparently precise reverse-engineering exercise would manufacture a denominator that the evidence does not provide.

The warrant creates a second clock

Cash revenue share is only one part of the disclosed arrangement. In 2022, Klaviyo also issued Shopify warrants covering up to 15,743,174 shares at an exercise price of US$0.01. The aggregate grant-date fair value was US$370.3 million. The consideration was for marketing services under the collaboration, so Klaviyo capitalises prepaid marketing expense as the warrants vest and amortises the asset over the seven-year expected benefit period.

That sequence is easy to misread because three events occur at different times. Vesting adds the grant-date value of the relevant warrant tranche to the prepaid marketing asset. Amortisation transfers part of the accumulated asset to selling and marketing expense. An eventual exercise affects shares and equity, but it is not the event that determines the grant-date marketing cost. The public-market value of Klaviyo’s stock is therefore not a quarterly remeasurement of the US$370.3 million asset.

The IPO introduced another discontinuity. Klaviyo says the listing accelerated 25% of the total warrants, adding US$92.6 million to prepaid marketing expense at that time. That historical acceleration helps explain why the expense schedule need not resemble the cash revenue-share schedule or the growth of Shopify-sourced business in any current quarter.

In the first half of 2026, vesting capitalised US$16.2 million. Amortisation recognised US$26.4 million. The prepaid asset declined from US$132.8 million at December to US$122.6 million at June. The US$10.2 million change equals amortisation less new capitalisation at the reported level of precision. It is an unusually useful reconciliation: investors can see both what entered the store of future benefit and what left it for the income statement.

At June, another US$163.1 million of warrant-related marketing expense remained unrecognised over 3.1 years. That is a future expense schedule, not a future cash bill of the same amount. Much of the consideration was fixed by a 2022 grant-date valuation. It will still affect reported operating leverage even if current-period cash revenue-share economics improve.

US$44.4 million is a bridge, not a bill

Adding US$18.0 million of revenue-share fees and US$26.4 million of warrant amortisation gives US$44.4 million of known Shopify-related expense in the first half. It represented 16.2% of Klaviyo’s US$273.4 million of selling and marketing expense and 6.1% of revenue. Those proportions make the arrangement visible at company scale.

But the sum joins two economically different items. The revenue-share fees are period costs payable under formulas tied to marketing services and qualifying merchant activity. The amortisation is non-cash recognition in the period of a prepaid asset arising from warrants valued years earlier. Saying that Klaviyo “paid Shopify US$44.4 million” would collapse the clocks and overstate current cash transfer.

The sum is also not a complete ecosystem contribution calculation. It lacks Shopify-attributed revenue, direct cloud and messaging cost for that cohort, merchant retention, expansion, support workload, sales coverage, integration engineering and any other partnership expense. Conversely, some Shopify-derived benefits may reach merchants or channels that the published fee mechanics do not let an outsider isolate.

The correct analytical move is therefore modest. Keep the two disclosed cost lines separate, show where they sit, and ask for the missing denominators. The exercise changes how one reads margin quality without pretending to recreate an internal partner P&L.

Operating leverage has a scheduled passenger

Klaviyo’s first-half selling and marketing expense increased by 9.3% while revenue increased by 27.2%. As a proportion of revenue, selling and marketing fell to 37.5% from 43.7%. That is genuine reported operating leverage. The Shopify bridge explains part of what is inside the line, not why the whole ratio improved.

The revenue share increased US$2.0 million year on year. Warrant amortisation was flat at US$26.4 million across the two half-years. A fixed scheduled charge becoming smaller relative to a growing revenue base helps the percentage even when no underlying partner contract becomes cheaper. At the same time, a variable fee growing more slowly than total revenue may reflect favourable mix—or simply more growth outside the measured Shopify perimeter.

This is why a single expense ratio cannot distinguish scale from composition. A company can produce operating leverage because sales staff become more productive, advertising grows slowly, warrant amortisation is fixed, partner sourcing shifts, or revenue expands outside the partner channel. These mechanisms have different durability. Only one of them says the next Shopify-sourced customer became more profitable.

The remaining US$163.1 million of scheduled warrant expense creates a partial forward map. If no accounting estimate changes, it will continue to run through selling and marketing as the older consideration is consumed. When that schedule tapers, reported leverage may improve mechanically. Analysts should not mistake the end of an amortisation clock for a sudden improvement in current distribution bargaining power.

The seven-year boundary is commercial as well as accounting

The collaboration began on 28 July 2022 with a seven-year term, followed by successive one-year renewals unless either party gives notice of non-renewal. Klaviyo uses the same seven-year term as the expected benefit period because the core activities and deliverables remain in place and Shopify does not have a convenience termination right under the disclosed arrangement.

That makes 2029 a useful boundary, not a predicted rupture. Product integration can continue, the agreement can renew, and commercial terms can evolve. The current disclosure does not say either party plans to leave. It does say that an accounting estimate, a contractual term and a distribution dependency converge around the same period.

The clocks will not necessarily finish together. Remaining warrant vesting follows its own schedule. Prepaid expense amortisation has a 3.1-year disclosed tail from June 2026. Revenue share continues under current-period merchant economics. Product integrations may generate costs and benefits beyond both. A renewal could preserve the relationship while changing the mix of cash fees, data access, product commitments or marketing obligations.

Waiting until the term boundary to construct a partner contribution history would be a mistake. Once cohorts, attributions and fee formulae change, prior-period economics become difficult to reconstruct from aggregate statements. Klaviyo can preserve that history internally now even if competitive sensitivity limits the public detail.

The missing receipt is contribution by ecosystem

A useful disclosure need not reveal merchant names or Shopify’s confidential contract terms. It could begin with five ranges: partner-attributed recurring revenue, the cash partner fee, direct messaging and infrastructure cost, retention and expansion for the cohort, and contribution after those items. A split between Core revenue share and Plus integration fees would make the movement intelligible without exposing individual accounts.

The cohort also needs a time dimension. New Shopify-sourced merchants may require marketing, migration and integration effort before generating mature contribution. Existing merchants may expand into text, WhatsApp or service interactions that lift revenue and delivery cost together. A twelve-month view that joins acquisition source, active integration, usage, renewal and retained gross profit would show whether the ecosystem toll buys durable economics.

Until that receipt appears, three disciplines improve the external reading. First, do not infer partner revenue from the 15% headline. Second, do not call warrant amortisation cash. Third, do not use reported gross margin as if it already deducted every cost that scales with a distribution ecosystem.

Klaviyo’s disclosure is better than a black box: it supplies the fee, the asset, the amortisation and the remaining schedule. The next step is not another adjusted margin. It is a contribution bridge that respects where the customer came from as well as what it cost to serve.

Sources