The published vendor data says texts convert around 0.1% as campaigns and 0.77% as automations. At a penny per message, that spread is the entire difference between a profit center and a subsidized hobby.
SMS is the channel retention people argue about most, because both sides are right. The skeptics are right that blasting texts at a list converts a fraction of a percent. The believers are right that a well-triggered text is the single highest revenue-per-send message in the stack. The published vendor data resolves the argument by splitting it: the channel does not have one ROI, it has two, and they differ by a factor of five to eight depending on whose dataset you read.
I want to lay out that math with only numbers that come from published reports and pricing pages I actually opened, because SMS suffers more than any channel from recycled statistics with no source attached.
Omnisend’s 2026 statistics roundup, drawing on 321 million SMS messages sent by 150,000 brands in 2025, is the most complete public dataset right now, and its campaign-versus-automation split is stark. Scheduled campaign texts averaged a 12.39% click-through rate across 246 million sends, which sounds spectacular next to email, but only 0.12% of sent messages converted, worth $0.15 in revenue per message. Automated texts, the ones triggered by a cart, a browse, a shipment, converted at 0.77% and generated $0.74 per send, roughly five times the revenue per message and more than six times the conversion rate.
Klaviyo’s 2026 SMS benchmarks, built on its 183,000+ customer base, tell the same story from a different angle: SMS flows account for just 7.6% of send volume but 45.2% of all SMS-attributed revenue, flow texts earn roughly 8 times the revenue per recipient of campaigns, and the top 10% of flows clear $5 per recipient. Two competing platforms, two independent datasets, one conclusion: the trigger, not the channel, is what pays.
The cost side is refreshingly concrete because it sits on public pricing pages. On July 16, 2026, Klaviyo’s calculator listed US toll-free SMS at $0.01 per send plus carrier fees, with a running monthly total displayed right on the page. Omnisend’s pricing page sells SMS credits on top of any plan, advertising rates starting at $0.007, and its US example package prices $50 of credit at 5,882 messages, which works out to $0.0085 per SMS. MMS costs more and every country differs, but for US sends the honest planning number is about a cent per message.
Put the two published numbers together and the unit economics are almost embarrassing. An automated text that returns the dataset-average $0.74 against a one-cent cost pays for itself 70 times over before you count platform subscription or the discount you may have embedded. Even the maligned campaign blast, at $0.15 revenue per message against a cent of cost, carries a 15x message-level return. The channel’s problem was never unit economics. It is that unsubscribes are silent, carrier complaints are expensive, and the message-level margin evaporates the moment a blast burns a hundred subscribers to win three orders.
This calculator uses the published benchmark rates as defaults, campaign or automated, and lets you swap in your own. It computes channel revenue against message cost for one send to your list. Every default carries its source in the label.
Benchmark conversion rates are per message sent (not per click) from Omnisend's 2026 SMS report; message costs from Klaviyo and Omnisend pricing pages, July 16, 2026. Result excludes platform subscription and any discount you embed in the text.
The default scenario, 3,000 subscribers and a $60 order, shows why the campaign-versus-flow choice dominates every other lever: flip the radio button and nothing else, and the expected orders change by a factor of six. No amount of copywriting on a blast closes a gap that size.
The math above flatters SMS because it prices one send in isolation. Three costs live outside it. Opt-in acquisition is the big one: an SMS list grows slower than an email list because the legal bar and the psychological bar are both higher, so the fixed effort of collection spreads over fewer subscribers at first. List burn is the second: every blast spends some goodwill, and unlike email, people rarely give you a second number. Deliverability compliance is the third; Omnisend’s report puts campaign deliverability at 96.6%, which is high, but the carrier filtering that produces the missing 3.4% gets aggressive quickly for senders who trip complaint thresholds.
That is why the sequencing I take from the published data is conservative: wire the automated flows first, cart, browse, shipping, winback, where 0.77% conversion per send does the work quietly. Add campaign blasts only for genuinely scarce moments, drops and last-chance windows, where urgency is real rather than manufactured. Klaviyo’s finding that 64.4% of SMS flow revenue comes from new buyers gives the final hint: the channel earns its keep early in the relationship, catching the customers your email program has not had time to reach. Treat it as a precision tool with a per-use cost, not a megaphone with a monthly fee, and the published numbers say it pays for itself many times over.
The published numbers say yes if you start with automated flows rather than blasts. At roughly a cent per message and $0.74 average revenue per automated send in Omnisend's 2026 data, even a small list produces positive channel margin. The risk is not cost per message, it is burning list goodwill with too many promotional blasts.
From published platform data, around 0.12% of sent campaign messages convert and around 0.77% of automated messages do. Treat anything you see quoted above 5% skeptically: that is usually click-to-conversion (share of clickers who buy), not conversion per send.
In the US, about a cent on the pages I checked in July 2026: Klaviyo lists $0.01 plus carrier fees for toll-free sends, and Omnisend lists $0.0085 per SMS at its $50 credit volume, starting from $0.007 at larger volumes. International rates differ a lot, so check the per-country tables before planning campaigns abroad.
No, it layers on top. The published data shows SMS flows excel at urgent, high-intent moments while email carries the narrative weight. Klaviyo's benchmark note that 64.4% of SMS flow revenue comes from new buyers suggests texts work hardest early in the customer relationship, exactly where email lists are weakest.