SMS or email for customer updates: how to choose
Decide which customer updates belong in a text message and which belong in email by cost per message and reply expectation and how much attention each one earns.
The question is not which channel is better
Somebody has told you that a text gets read where an email does not and somebody else has told you that every text costs money while email is nearly free. Both are right. The decision is not which channel wins. It is which of your messages deserve to interrupt somebody and which should sit in an inbox until they are wanted.
Email is cheap storage and patient attention. A text message is expensive attention that arrives immediately and expects an answer. Sorting your updates by that difference settles most of the argument without a trial.
What each one costs and what neither covers
Neither channel covers the content. Writing and offer design and the landing page sit outside both and they are the part that decides results. A business with nothing useful to say gets a quieter failure on email and a louder one by text.
Email costs a subscription scaled to the contacts you store plus production per campaign. The marginal cost of one more send is close to nothing. Text messaging costs per message segment with the rate depending on the message type and the destination plus a provider fee in most setups and a registration step before a business number can send at volume. Its marginal cost is real. Rates are stated before tax. Sales tax on marketing services varies by state.
Text messaging carries one cost email does not. Staffing. A message that arrives on a phone invites a reply within minutes. Budget for somebody to answer or do not send.
Who should use which and who should use neither
Do not put text messaging in front of customers if nobody is rostered to answer replies. A business that broadcasts on Friday evening and reads the responses on Monday has paid for the message and then taught the recipient that writing back is pointless. Email is the correct channel for an organisation that cannot staff conversations and that is not a criticism of the organisation.
Do not rely on email alone if your updates are time critical and your customers are not desk workers. A delivery window or a service engineer's arrival or an expiring payment link reaches a site foreman or a shopkeeper on a phone and not in a webmail tab they open twice a week.
Businesses with both kinds of message need both channels and a rule separating them. Price the messaging half of the split separately from the email half so you can see which one you are actually paying for.
How to split your updates between them
Sort every recurring message you send by two questions. Does it lose value if read tomorrow. Does it invite a reply. Anything that loses value overnight and expects a reply belongs in a text. Order confirmations and dispatch and delivery updates and appointment reminders and failed payment notices all qualify.
Everything else belongs in email. Newsletters and product announcements and offers and educational content and reactivation sequences are all equally useful tomorrow. They also tolerate length and multiple links which a text message handles poorly.
Then run them from one contact record rather than two lists. If the same customer gets a text about dispatch and an email asking whether their order arrived the two channels are working against each other. Whichever system holds the authoritative status should suppress the other.
How to judge the split
Delivery rate is the flattering comparison and it is the one everybody reaches for. Text messaging will win it every time because the message lands on a device already in somebody's hand. It says nothing about whether the interruption was welcome or whether anything followed.
Judge each channel on cost per completed action and on one discomfort metric. For email that is unsubscribe rate and spam complaints. For text messaging it is the opt-out rate. Opt-outs are the more serious of the two because they feed the carrier filtering that decides whether your messages arrive at all and that filtering also catches the transactional sends you cannot afford to lose.
The common mistake
The expensive error is migrating the email programme to text because the read rates looked better in a deck. The newsletter becomes a text and the offer calendar moves across and within two months the opt-out rate has risen enough for carriers to start filtering your traffic. The casualty is not the newsletter. It is the order confirmation that now fails to send on a busy day.
The mirror error is cheaper but still costs money. Businesses push urgent operational updates through email because email is already paid for. Those messages compete with marketing in the same inbox and in the same reputation. A delivery notice that lands in a promotions tab has not been delivered in any sense that matters to the customer waiting at home.
This guide explains how something works. It is not legal, tax or financial advice, and rules change. Confirm anything regulatory with a qualified professional before you act on it.