For an online store, the platform fee is only the first line of the bill. Klaviyo charges for every reachable profile in your database, Omnisend now reserves SMS for its top plan, Postscript charges per text plus carrier fees — and Attentive does not publish a price at all. This guide compares the four on how the money actually works.
At 251–500 active profiles. Free up to 250 profiles. SMS is billed per message on top.
Standard at 500 contacts. Pro from $59/mo — and for newer accounts, SMS requires Pro.
Starter carries a $49/mo minimum spend, then per-message and carrier fees. SMS only — no email.
Quote-based only. There is no list price, free tier or self-serve signup to compare against.
| Klaviyo | Omnisend | Postscript | Attentive | |
|---|---|---|---|---|
| Best for | Stores that segment hard and run email + SMS together | Small-to-mid stores wanting ecommerce automation without a big entry price | Shopify stores treating SMS as a primary channel | Large DTC and retail brands with a messaging budget and a sales process |
| Channels | Email + SMS/MMS + WhatsApp + push | Email + SMS + web push | SMS/MMS (and RCS) only — no email product | SMS + email + RCS + push |
| What you are billed on | Active profiles: anyone with an email address who is not suppressed counts — buyers, checkout starters and form signups included, whether or not you send to them | Billable contacts: subscribers plus non-subscribers who received an automated message; unsubscribed contacts are not billed | Messages sent. No profile or contact fee | Not published; quoted per account, based on volume and scope |
| Free option | Yes — up to 250 active profiles, 500 email sends/month, $5 of mobile messages/month | Yes — up to 250 contacts, 500 emails/month, full feature set | No free plan — 30-day trial with a $100 usage credit | None published |
| Published starting price | Email $20/mo at 251–500 profiles; $150/mo at 10,000; $720/mo at 50,000 | Standard $16/mo at 500 contacts (about $132/mo at 10,000); Pro $59/mo up to 2,500 contacts ($150/mo at 10,000) | Starter $0 platform fee with a $49/mo minimum spend; Growth $100/mo; Professional $500/mo | Not published — every tier routes to a sales quote |
| US SMS cost | Per-message, dollar-based since July 2026; rates vary by channel and country (the retired credit system worked out to roughly $0.012/message) | Roughly $0.007–0.009 per message by volume — Pro plan only for accounts created on or after May 4, 2026 | $0.009 / $0.008 / $0.007 per SMS by plan (Starter / Growth / Professional), plus carrier fees passed through at cost (US average roughly $0.0033 per SMS) | Not published |
| Trade-off to know | Excluding people from campaigns does not cut the bill — only suppressing profiles does. Crossing a tier moves you up automatically | The headline Standard price does not include SMS for newer accounts; budget for Pro if texting is the point | The per-text rate is not the whole text cost: carrier fees ride on top, and email is a separate subscription elsewhere | You cannot comparison-shop the price, and third-party "estimates" of Attentive pricing are not vendor figures |
Prices are USD, before tax, as published in November 2026. Prices checked November 2026 — some vendors do not publish pricing: Attentive publishes tier names but no dollar figures, so no Attentive number appears anywhere in the table or the worked example below. Klaviyo replaced SMS credits with dollar-based per-message rates in July 2026; articles still quoting credit bundles are out of date. Plans and rates change — confirm the current figures on the vendor's site before you buy.
The model store: 10,000 reachable email profiles/contacts · 4 email campaigns a month to the full list (40,000 sends, inside every plan's allowance below) · an SMS list of 3,000 · 2 SMS campaigns a month = 6,000 US text messages, one segment each. Figures are our arithmetic on the published prices above — not vendor quotes, and not a promise of results.
| Platform | How the monthly figure is built | Per month | Per year |
|---|---|---|---|
| Klaviyo (email + SMS) | Email at the 10,000-profile tier $150 + 6,000 texts at roughly $0.012 ≈ $72 | ≈ $222 | ≈ $2,664 |
| Omnisend Pro (email + SMS) | Pro at 10,000 contacts $150 (unlimited email) + 6,000 texts at $0.007–0.009 = $42–54 | ≈ $192–204 | ≈ $2,304–2,448 |
| Omnisend Standard (email only) | About $132 at 10,000 contacts — but newer accounts cannot send SMS on Standard, so this is not an email + SMS option | ≈ $132 | ≈ $1,584 |
| Postscript Starter (SMS only) | $0 platform fee + 6,000 × $0.009 = $54 + carrier fees 6,000 × $0.0033 ≈ $19.80 (the $49 minimum is already covered) | ≈ $73.80 | ≈ $886 + your separate email bill |
| Postscript Growth (SMS only) | $100 + 6,000 × $0.008 = $48 + ≈ $19.80 carrier fees | ≈ $167.80 | ≈ $2,014 + email |
| Attentive | No published pricing — this row cannot be calculated, which is itself the finding | — | — |
Three things the arithmetic shows. First, Postscript looks cheapest until you remember it is SMS only — the email platform still has to be paid for. Second, Postscript's higher tiers do not pay off at this volume: moving from Starter to Growth saves $0.001 per text ($6/month at 6,000 texts) while adding a $100 platform fee. Tier upgrades in per-message pricing only make sense when the volume math says so. Third, Klaviyo's real cost lever is not in this table at all — it is your profile count. If this store's database holds 25,000 active profiles (past buyers, checkout starters, old imports) behind its 10,000 subscribers, the email line alone becomes $400/month instead of $150: an extra $3,000 a year for people it may never email.
Klaviyo is built around a single customer profile that email, SMS, WhatsApp and push all read from, with segmentation and predictive analytics layered on top. The free plan covers up to 250 active profiles and 500 email sends a month. Paid Email plans start at $20/mo (251–500 profiles) and climb by profile band — $100/mo at 5,000, $150/mo at 10,000, $400/mo at 25,000, $720/mo at 50,000 — with a send allowance of roughly ten times your profile tier. Above 150,000 profiles, pricing is custom. SMS is a separate, per-message charge: since July 2026 it is billed in dollars at rates that vary by channel and destination country, replacing the old credit bundles.
The definition that decides your invoice: an active profile is any contact that can receive marketing — subscribers, yes, but also customers who bought without subscribing, shoppers who started a checkout, and people who typed an email into a form. Since February 2025, Klaviyo bills on all of them, not just the ones you recently emailed. Suppressed and unsubscribed profiles are not billed — and suppression, not campaign exclusion, is the only switch that lowers the count.
Omnisend is an ecommerce-first platform combining email, SMS and web push with pre-built automation for welcome series, cart recovery and post-purchase follow-up. Its free plan ($0, up to 250 contacts and 500 emails/month) is unusual in this category: the feature set is the paid feature set — automations, segmentation, forms — with volume, not features, as the limit. Standard starts at $16/mo for 500 contacts (sends up to 12× your contact count; about $132/mo at 10,000 contacts). Pro starts at $59/mo up to 2,500 contacts ($150/mo at 10,000), with unlimited email sends under fair use.
The change to price in: for accounts created on or after May 4, 2026, SMS sending is Pro-only. US SMS rates run roughly $0.007–0.009 per message by volume. Older guides describing SMS credits bundled with Pro, or SMS on every plan, describe a structure new accounts no longer get — check which structure your account is on before comparing totals. Billing counts "billable contacts": subscribers plus non-subscribers who received an automated message (an order confirmation, a cart reminder), while unsubscribed contacts are not billed.
Postscript does one channel: SMS (and RCS) for Shopify stores. There is no email builder and no email bill — and no free plan, though a 30-day trial includes a $100 usage credit. Starter has a $0 platform fee with a $49 monthly minimum spend, at $0.009 per SMS and $0.045 per MMS. Growth ($100/mo) drops the rates to $0.008 / $0.03, and Professional ($500/mo) to $0.007 / $0.024. On every plan, carrier fees are added at cost — the vendor publishes US averages of roughly $0.0033 per SMS — and the vendor states there are no profile fees, no prepaid balances, no expiring credits and no auto-upgrades.
That transparency cuts both ways in your budgeting: the advertised $0.007–0.009 is never the full per-text cost, because carrier fees ride on top, and longer messages use more than one segment. But unlike a bundled credit system, every layer of the charge is printed before you commit, so a store can model its real cost per campaign in advance — as the worked example above does.
Attentive positions SMS, email, RCS and push as one managed messaging program for larger consumer brands, with an emphasis on list growth tooling, conversational messaging and deliverability support. What it does not position anywhere public is a price: the vendor publishes no rates, no tiers with dollar figures, no free plan and no self-serve signup. Every route leads to a sales quote, and terms such as minimum spend, contract length and overage handling are set in that negotiation rather than on a pricing page.
We include Attentive because stores comparing SMS platforms will meet it in every shortlist — and because "price not published" is decision-relevant information, not a gap to fill with guesses. Figures for Attentive that circulate in third-party articles are estimates built from other companies' contracts; they are not vendor prices, so this guide does not use them in the table, the worked example, or anywhere else. If Attentive is on your list, the only honest cost figure is the quote itself — ask for the minimum spend, the term, what happens to unused volume, and the overage rate, in writing.
Profiles you hold (Klaviyo), contacts you keep (Omnisend), messages you send (Postscript), or a negotiated program (Attentive). The billing unit matters more than the starting price, because it decides what makes your bill grow: list size, send volume, or neither in public view.
Before comparing prices, export your database and count it three ways: subscribers, everyone with an email address who is not unsubscribed, and last year's buyers who never subscribed. On profile-based billing the second number — not the first — is your tier. Then price suppression into the routine: it is the only lever that reduces a profile bill.
Take last month's (or your planned) text count and price it completely: platform fee or minimum + per-message rate + carrier fees, at the plan you would actually be on. Remember Omnisend's SMS is Pro-only for newer accounts, and that a cheaper per-text rate only wins when volume × the saving beats the higher platform fee.
Klaviyo and Omnisend both have real free tiers — run one actual campaign and one cart flow through each. Postscript's trial credit lets you test SMS economics. For Attentive there is no test tier, so start the quote conversation early and get minimums, term and overage terms in writing before it becomes the deadline option.
Because Klaviyo bills on active profiles, not sends or subscribers. An active profile is anyone in your account with an email address who is not suppressed — including past buyers, checkout starters and form signups who never opted in to marketing. Since February 2025 that whole count sets your tier. Excluding a segment from campaigns does not change the bill; suppressing those profiles does.
On published US pricing: roughly $0.007–0.009 per message on Omnisend Pro and on Postscript's plans, with Postscript adding carrier fees (US average roughly $0.0033 per SMS) on top, so budget around $0.010–0.013 all-in per one-segment text there. Klaviyo moved to dollar-based per-message rates in July 2026 that vary by channel and country. Attentive does not publish a per-message rate. Longer texts count as multiple segments everywhere.
For the SMS line alone, it can be — our worked example puts Postscript Starter at about $74/month for 6,000 texts. But it sends no email, so the honest comparison is Postscript plus your email platform against the all-in-one total. Run both sums at your own volumes before concluding either way.
There is no published answer. Attentive lists no prices publicly and sells by quote, so any specific figure in a third-party article is an estimate from other buyers' contracts, not a rate you can rely on. The vendor's quote — including minimum spend, contract term and overage terms — is the only real number.
Both free tiers cap at 250 contacts/profiles and 500 emails a month — enough for about two full-list sends. Omnisend's free plan unlocks the full feature set (automations included), which makes it the broader testbed for features; Klaviyo's free tier includes $5 of mobile messages a month, a small head start on testing SMS. Neither free tier supports a serious SMS program: Omnisend reserves SMS for Pro on newer accounts, and Postscript has no free plan at all.
No — and this guide repeats no such promise. Vendors publish their own performance claims about their customers' results; those are the vendors' claims, based on their chosen data, and they are not a guarantee for your store. Judge a platform on its published prices, billing rules and features, then on what your own trial campaigns actually do.
Because this comparison is compiled from publicly available vendor information — pricing pages, billing documentation and published plan terms — not from hands-on testing. Every judgment above is either a published specification or arithmetic on published prices, shown next to the numbers so you can re-run it yourself.