Your two messaging channels side by side. Email is high-volume and near-free; SMS is low-volume, paid, and converts harder per send. This card shows the balance you are striking.
At a glance
A grouped-bar comparison of SMS send volume against email send volume per period bucket, so you can see the channel mix at a glance. The two channels behave very differently: email is high-volume and effectively free per send, while SMS is low-volume, consent-gated, billed per message, and typically converts much harder per send. This card exists to make the trade-off visible, because the right channel mix is not “send everything on both” but “use email for reach and SMS for high-intent moments where its higher per-message return justifies the cost”. Reading the two bars together stops you from over-investing in expensive SMS volume that is not converting, or from leaning so hard on email that you under-use the higher-value channel. It is a planning view, not an alert view: use it to decide where the next message should go.
| What it counts | Email send volume and SMS send volume per period bucket, plotted as grouped bars for direct comparison. |
| API endpoint + statistics field | POST /api/campaign-values-reports and POST /api/flow-values-reports, returning the recipients statistic per channel, split into email and SMS series. |
| Email vs SMS aggregation | Both channels, shown side by side rather than blended. Each bar is a separate channel total for the bucket. |
| MPP impact | None. Apple Mail Privacy Protection affects email opens only, not send counts, so neither bar is distorted by MPP. |
| Chart type | Grouped bar. |
| Time window | 30D vsP |
| Alert trigger | A pronounced shift in the channel mix against the recent baseline, for example a surge in SMS volume, which on a paid channel warrants a spend and return check. |
| Roles | owner, marketing |
Calculation
Calculated automatically from your Klaviyo data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
An illustrative gifts brand that uses email broadly and SMS selectively for time-sensitive offers. Reading the dashboard on 14 Apr 26 for the trailing 30 days (14 Mar 26 to 12 Apr 26), the grouped bars by week look like this (illustrative figures):| Week | Email sends | SMS sends | SMS share of sends |
|---|---|---|---|
| 14-20 Mar 26 | 96,000 | 6,000 | 5.9% |
| 21-27 Mar 26 | 98,000 | 6,200 | 5.9% |
| 28 Mar-3 Apr 26 | 99,000 | 12,400 | 11.1% |
| 4-12 Apr 26 | 101,000 | 12,800 | 11.3% |
- Email dwarfs SMS on raw volume, and that is normal. Email runs roughly sixteen times the SMS volume here. The point of the card is not to close that gap but to show the balance, because the channels play different roles.
- The SMS bar grew in weeks 3 and 4 for a flash sale. SMS share doubled from about 6% to 11%. This is the deliberate use of a paid, high-intent channel for a time-sensitive moment, exactly where SMS earns its cost.
- Cost asymmetry is the whole reason to compare. Adding email volume is nearly free; adding SMS volume is real spend. So a rising SMS bar is a spending decision, and this card is where you notice it before the bill does.
- Lower SMS volume can still out-earn its share. Because SMS revenue per recipient typically runs well above email, the small SMS bar can contribute a disproportionate slice of revenue. Read this alongside Revenue per Send to see value, not just volume.
- Use the mix to plan, not to equalise. The aim is not to make the bars match. It is to send email for broad reach and reserve SMS for moments where its higher per-message conversion justifies the cost. If the SMS bar grows without conversion keeping up, pull it back.
Sibling cards merchants should reference together
SMS vs Email Sends is the channel-mix planning view. Pair it with these:| Card | Why pair it with SMS vs Email Sends |
|---|---|
| Total Sends | The all-up email volume behind one of the bars. Use it to drill into the email side of the mix. |
| SMS Sends | The SMS bar in detail, including its role as your SMS spend line. |
| SMS Overview | The cockpit view of the SMS side, so a growing SMS bar can be judged on its returns. |
| Email Attributed Revenue | The email payoff. Pair send volume with revenue to weigh email reach against SMS value. |
| Revenue per Send | The value-per-message read. This is what tells you the cheaper channel is not always the better one. |
Reconciling against Klaviyo
Where to look in Klaviyo:- Klaviyo → Analytics → Performance, then compare the email and SMS channel views over the same period.
- Klaviyo → Campaigns, filtered by channel, to see email and SMS recipient counts side by side.
- Klaviyo → Flows, filtered by channel, for triggered email and SMS volume.
| Reason | Direction of divergence |
|---|---|
| Channel scoping. Klaviyo’s default dashboards often show one channel at a time, so a single-channel view will only match one of our two bars. | Matches one bar, not both. |
| Time zone. Vortex IQ buckets by UTC day; Klaviyo uses your account time zone. Messages near midnight can fall into a different period. | Either direction, usually marginal. |
| Campaign plus flow scope. Each bar blends campaigns and flows. A campaign-only Klaviyo view will read lower on the corresponding bar. | Ours reads higher than a campaign-only view. |
| Carrier filtering (SMS only). Some SMS messages are filtered at the carrier and may be counted differently between a live view and our snapshot. | SMS bar can read marginally low. |
| Page caps. Values reporting pages at 50 records per pull, so very high volumes can see slight aggregation truncation on either series. | Either bar can read marginally low for heavy senders. |