SMS marketing cost depends on the audience, the destination, and the number of segments in the finished message. A draft that looks inexpensive can expand after a name, a link, or a translation is inserted. Estimate those parts separately for your Shopify campaign, then compare the expected cost with a realistic commercial goal before scheduling the send.
Estimate the actual campaign
Use current Sendvio pricing and the campaign's own estimates rather than rates copied from an old article. Check how many eligible recipients remain after subscription and validation exclusions. Keep attempted sends, delivered messages, and segment usage distinct in your notes.
Preview the longest realistic message. Include sender identification, links, personalization, and the opt-out information required for the destination. Review each language separately because character encoding can affect segmentation.
Calculate the estimate in separate parts
For each destination group, multiply eligible recipients by estimated message segments and the current applicable rate, then include any other charges shown by your account's pricing or estimate. Sum the groups rather than assuming one rate applies to every number. Keep the assumptions visible so a copy or audience change can be recalculated quickly.
An illustrative audience of 800 recipients with a two-segment message creates 1,600 outbound segments before other factors or charges. If a revision makes the final message three segments, the estimate becomes 2,400 segments. That is a meaningful difference even though the text may look only slightly longer. Use actual rates from the account; these counts are not a price quote.
Do the calculation after adding the real link, personalization, sender identification, and required opt-out information. Review translations independently. A budget based on the shortest draft can be wrong for the longest rendered message or a different encoding.
Set a commercial limit
Decide what the campaign can reasonably spend before activation. Include the discount cost and fulfillment implications, not just messaging charges. A high order value can hide a weak contribution if the offer is expensive to honor.
Start with an audience whose interest you can explain. Sending a concise restock update to eligible customers who requested it may provide clearer evidence than testing a broad promotion on every reachable number.
Define the commercial decision before activation
Write down the maximum planned messaging spend, the offer's cost, and the outcome the campaign is intended to support. A restock alert to interested subscribers has a different rationale from a broad discount promotion. The same channel cost can be reasonable for one use case and wasteful for another.
Consider contribution rather than gross sales alone. Product cost, fulfilment, payment costs, discounts, shipping subsidies, and expected returns affect what an order leaves for the business. Avoid double-counting a discount if the revenue figure already reflects it. Use the same finance definition when comparing campaigns.
Review the result with consistent definitions
Compare revenue or orders per recipient using the same attribution rules and observation period. Attributed sales do not automatically equal incremental sales, so avoid presenting all credited revenue as money the campaign created by itself.
Record channel cost, offer cost, opt-outs, and the decision for the next send. If the economics are weak, inspect relevance and the destination before simply shortening the copy or increasing volume. A useful budget helps you choose where SMS adds value and where email or no message is the better decision.
After the send, reconcile the estimate with actual segment usage and charges. Investigate differences caused by audience changes, rendered content, destinations, or other pricing components. This turns the next estimate into a better planning tool rather than repeating the same rough guess.
Keep attribution separate from incrementality. A report may credit orders to the campaign under a chosen window without proving all those customers would otherwise have stayed away. Where practical, use a suitable comparison or holdout and acknowledge uncertainty for small groups. Decide whether to repeat the campaign based on relevance, customer response, and the full economics. If the case is weak, improving the audience or choosing no SMS may be more useful than cutting one essential sentence to save a segment.