Klaviyo’s Rumored Shopify Exclusivity Push Is Alarming Rival ESPs

Something is shifting inside the Shopify app ecosystem, and it’s making the email and SMS marketing vendor community deeply uneasy. Multiple sources familiar with ongoing platform negotiations tell Ecommerce Times that Klaviyo — already the dominant ESP among Shopify merchants — is allegedly in advanced conversations with Shopify to secure a level of preferred-partner status that goes well beyond its current co-marketing arrangements. If the unconfirmed terms hold, the deal could reshape how tens of thousands of merchants discover and adopt email and SMS tooling.

Sources close to the matter say the discussions involve Klaviyo receiving prioritized placement in Shopify’s onboarding flows, including the post-signup merchant checklist that guides new store owners through their first app installations. That checklist, which Shopify reportedly sees by more than 400,000 new merchants per quarter, is effectively a demand-generation machine for any vendor lucky enough to appear in it. Being the default recommendation in that flow — rather than simply appearing in search results — is, as one agency founder put it, “worth more than $10 million in paid acquisition.”

What Are the Alleged Terms of the Klaviyo-Shopify Deal?

According to two sources with knowledge of the negotiations — both of whom requested anonymity due to the sensitivity of the discussions — Klaviyo has reportedly proposed a revenue-share arrangement tied to merchant lifetime value rather than a flat referral fee. This would give Shopify a financial incentive to keep Klaviyo-activated merchants on the platform longer, theoretically aligning both companies’ retention interests. In exchange, Klaviyo allegedly receives algorithmic prioritization in app category rankings for “Email Marketing” and “SMS & Push” — the two highest-traffic app store categories for DTC operators.

“If this is real, it’s not a partnership — it’s a toll booth. Every ESP that isn’t Klaviyo just got priced out of organic discovery,” said one senior product leader at a competing email platform, speaking on condition of anonymity.

Shopify has not publicly commented on the matter. Klaviyo’s communications team did not respond to a request for comment by press time. The alleged deal remains unconfirmed, and it’s possible the negotiations are at an exploratory stage that may not result in a formal agreement.

Why Would Shopify Agree to Preferred Vendor Arrangements?

The timing isn’t arbitrary. Shopify’s Q1 2026 earnings call — led by President Harley Finkelstein — emphasized the company’s push toward “deeper platform integrations” with what Finkelstein reportedly called “category-defining partners.” Analysts at Bernstein interpreted that language as a signal that Shopify is moving toward a tiered partner model, similar to what Salesforce runs with its AppExchange ISV program.

For Shopify, the financial logic is straightforward. Klaviyo went public in September 2023 and has since grown its merchant base to a reported 157,000+ customers as of its most recent earnings disclosure. Roughly 80% of those customers are on Shopify. A deeper commercial relationship would give Shopify a share of Klaviyo’s subscription revenue — which crossed $900 million ARR in early 2026 — without requiring Shopify to build competing email infrastructure.

“Shopify already owns the checkout. If they also control what happens to the customer data after the sale — through a preferred Klaviyo relationship — they’ve effectively captured the entire merchant revenue stack,” said Kunle Campbell, founder of 2X eCommerce and a widely followed Shopify strategy commentator.

Which Competitors Are Most at Risk?

The vendors watching this most nervously, according to agency sources, are Attentive, Omnisend, and Postscript — three platforms that have each built significant Shopify merchant bases and rely heavily on the app store’s organic discovery engine for new customer acquisition.

• Attentive, which reportedly serves over 8,000 e-commerce brands and raised $1.1 billion in total funding, has leaned heavily into SMS-first positioning. But sources say its Shopify merchant growth rate has already slowed in Q1 2026 compared to the same period last year.
• Omnisend, a bootstrapped platform popular with mid-market Shopify operators, derives an estimated 60–70% of its new signups from Shopify app store search — making any algorithmic demotion potentially catastrophic for its pipeline.
• Postscript, the SMS-focused platform backed by Greylock Partners, has allegedly begun internal conversations about diversifying its go-to-market strategy away from Shopify app store dependency, per one source familiar with the company’s planning discussions.

None of the three companies responded to requests for comment before publication.

How Are Shopify Agencies and Partners Reacting?

Among Shopify Plus agencies — the implementation partners who often recommend tooling to enterprise merchants — the reaction has ranged from cautious concern to open frustration. Several agency leaders told Ecommerce Times they worry a Klaviyo exclusivity arrangement would compromise their ability to recommend best-fit solutions to clients whose needs may not align with Klaviyo’s pricing tier or feature set.

“We have clients doing $3 million a year who are perfectly served by Omnisend at $400 a month. If Klaviyo becomes the de facto Shopify recommendation, we’re being asked to push a $1,200-a-month solution onto a merchant who doesn’t need it. That’s not good agency work — that’s a kickback structure dressed up as a partnership,” said Andrew Youderian, founder of eCommerceFuel and a respected voice in the independent Shopify agency community.

The concern echoes broader industry anxieties about platform consolidation. Earlier this year, Ecommerce Times reported on Shopify’s app store review algorithm changes that quietly reduced visibility for lower-rated apps, a shift that disproportionately affected smaller, independent developers. Critics saw that move as the beginning of a deliberate curation strategy — one that could now be extending into commercial exclusivity agreements.

What Does This Mean for the Broader ESP Market?

If the Klaviyo-Shopify arrangement does materialize in anything close to the form described by sources, the downstream effects on the ESP competitive landscape would be significant. Market intelligence firm Momentum Commerce estimates that Shopify-sourced leads account for between 40% and 65% of new customer acquisition for mid-tier ESPs — a dependency that has never been formally stress-tested against a deliberate platform preference toward one vendor.

There’s also a regulatory dimension worth watching. The EU’s Digital Markets Act, which came into full enforcement in March 2024, includes provisions against self-preferencing by “gatekeeper” platforms — though Shopify has not been formally designated as a gatekeeper under that framework. In the United States, the FTC’s 2025 platform competition guidelines, released under Chair Andrew Ferguson, flagged preferred placement deals between app marketplaces and third-party software vendors as a potential area of scrutiny, though no formal action has been announced against any e-commerce platform operator.

• Klaviyo currently holds an estimated 43% share of the Shopify merchant email marketing segment, per data from Analyzify’s 2026 Shopify App Market Report.
• The next closest competitor, Omnisend, holds approximately 18% share among active Shopify stores using dedicated ESP apps.
• Attentive and Postscript together account for roughly 22% of Shopify merchants using SMS platforms.

Is There Any Scenario Where Rivals Benefit From This?

Counterintuitively, some observers believe the alleged Klaviyo move could accelerate investment and differentiation among competing ESPs — forcing platforms like Omnisend, Drip, and the newly relaunched Sendlane to compete on product depth rather than app store visibility.

“If Klaviyo gets the Shopify firehose, everyone else has to get really good at winning on LinkedIn, at conferences, through agencies, through word of mouth. That’s actually how great products get built — not by riding a marketplace algorithm,” said Cody Iverson, co-founder of Videowise, a Shopify app vendor who has watched platform algorithm shifts affect his own business firsthand.

There’s also a meaningful segment of Shopify merchants — particularly those above $5 million in annual revenue — who are already making tooling decisions through agency recommendations and peer networks rather than app store discovery. For that segment, a Shopify-Klaviyo preferred arrangement may be largely irrelevant.

Still, for the thousands of merchants starting out on Shopify each week, default recommendations carry enormous weight. And if Klaviyo does secure what sources describe as a structural onboarding advantage, the competitive map for ESP vendors serving the Shopify ecosystem will look materially different by Q4 2026 — holiday season included.

Ecommerce Times will continue to monitor this story. If you have direct knowledge of the Klaviyo-Shopify negotiations, contact our editorial team securely.