Klaviyo Agency Los Angeles

The short answer

Tack Media implements and runs Klaviyo for ecommerce and subscription brands: account setup, data integration, flow architecture, segmentation, deliverability and reporting. We build the events Klaviyo cannot see on its own, then use them. Engagements start at $5,000 a month.

What we actually do with Klaviyo

Klaviyo is very good at using data it has been given and completely blind to data it has not. The difference between an account producing a modest share of revenue and one producing a serious share is almost always the data layer, not the copy.

• Account and data setup. Store integration, custom properties defined deliberately rather than accumulated, and event tracking for the behaviour that actually predicts a purchase.
• Flow architecture. Welcome, browse abandonment, cart and checkout abandonment, post-purchase, replenishment, winback, and the sunset flow most brands skip. Built as a system with entry rules that do not overlap.
• Segmentation that reflects the business. Not just engagement windows. Purchase frequency, category affinity, margin, subscription status and anything else your CRM knows.
• Custom event integration. Offline purchases, support tickets, appointment bookings and CRM stage changes pushed in through the API so flows can react to them.
• Deliverability work. Authentication, dedicated sending domain, list hygiene, sunset policy, and engagement-based sending. Sending to everyone is how a brand loses the inbox.
• SMS where it earns its place. Consent captured correctly, cadence agreed, and revenue reported separately from email so the comparison is honest.
• Reporting. Flow and campaign revenue surfaced in Looker Studio next to ad spend, so email is measured on the same basis as everything else.

What it connects to

Where teams get stuck

Billing is based on profiles you forgot you had. Klaviyo defines an active profile as any profile, regardless of consent status, that can be emailed through Klaviyo, with billable profiles being those able to receive at least one type of marketing. That includes people who left an email at checkout without ever opting in. Suppressed and deleted profiles drop out, but Klaviyo notes suppression processing takes up to 72 hours. A list nobody prunes is a bill that grows on its own.

Bulk syncs die on rate limits. Klaviyo enforces a one-second burst window and a one-minute steady window at the same time, with tiers ranging from 1 request per second and 15 a minute up to 350 a second and 3,500 a minute, returning HTTP 429 with a Retry-After header. Requests using include or additional-fields parameters get stricter limits again. Any migration or nightly sync written without backoff will fail partway and leave the data inconsistent.

The API version was pinned and forgotten. Klaviyo uses date-based revisions. As of 26 August 2026 the current revision is v2026-07-15, with versions available back to v2022-10-17, and authentication is by private key, OAuth or a public company ID for client-side endpoints. Integrations built years ago against an old revision keep working until they do not. We track revisions and upgrade deliberately.

Deliverability collapses slowly, then all at once. Sending to unengaged profiles to hit a revenue number works for about two quarters. Then inbox placement drops, the flows that were performing stop performing, and recovery takes months. A sunset policy costs revenue this quarter and protects it permanently.

How it works — 1, 2, 3

1. Audit and access, week 1 to 2. Account, integrations, flows, segments, deliverability signals and billable profile count. You get a written audit with the flows that are missing and the profiles you are paying for without reason.
2. Build and connect, week 3 to 8. Data integration, custom events, flow architecture built and tested, templates rebuilt, deliverability corrected, and reporting connected. Flows go live in sequence, not all at once.
3. Run and report, ongoing. Campaign calendar, flow testing, segment maintenance, list hygiene and monthly reporting on flow versus campaign revenue.

What it costs

Tack Media engagements start at $5,000 a month. What moves the number: list size, how many flows, whether custom event integration is required, whether SMS is in scope, and whether we run the campaign calendar or only the systems behind it.

Your Klaviyo subscription is separate and stays in your name. Klaviyo bills on billable profiles and monthly email volume, with mobile messaging priced in dollars that vary by channel, country, number type and carrier. Current tiers are published on Klaviyo’s pricing page and change, so check it against your actual profile count before budgeting. Retention work usually sits alongside paid media and CRO and marketing systems.

Questions we get asked

Who owns the Klaviyo account?

You do. It is your subscription, your list and your data. We work as users inside it. If we stop working together we are removed and every flow, template and segment stays exactly as built.

Can we take it in-house later?

Yes. Flows are documented, naming is consistent and segment logic is written down. We run a handover session with whoever is taking over, including the deliverability rules that are easy to break by accident.

Do you work with our existing account?

Usually. We keep flows that perform, fix the ones with overlapping entry rules, and rebuild only what needs rebuilding. Wholesale replacement loses historical performance data for no good reason.

Will you reduce our bill?

Often, yes, by suppressing profiles that will never buy and were never going to. That lowers the billable count and improves deliverability at the same time. We show the arithmetic before we do it.

What if we already have an email agency?

Then we can build only the data layer, the custom events and the integrations between Klaviyo, the store and the ad platforms, and leave the campaign work with them. That split works well.

The bottom line

Klaviyo performs in proportion to the data it can see and the discipline of the list behind it. Most underperforming accounts are not short of ideas, they are short of events, segments and a sunset policy.

For a straight read on what your account is missing, book a call with a Tack Media expert or phone 310-620-1141.

Sources

• Klaviyo Help Center — How Klaviyo billing works
• Klaviyo Developers — Rate limits and error handling
• Klaviyo Developers — API overview and versioning
• Klaviyo — Pricing