Text message advertising works differently from every other ad channel you buy: you cannot pay to put a text in front of strangers. You can only advertise by text to people who have already agreed to hear from you. So the real work is building that opted-in audience, then measuring what each advertising text produces. This article answers that question for a services firm of 10 to 250 people: where the audience comes from, how to capture consent at each entry point, and how to attribute bookings and revenue to the texts you send.
The audience is the asset
With search or social ads you rent an audience for as long as you pay. With text, you build one and keep it. Every person who opts in becomes a contact you can reach at the cost of a message, and the value of that list grows each month you add to it without abusing it.
That changes where the budget goes. Instead of spending on the text itself, which costs little, you spend on the routes that bring people in: a paid social ad that offers a useful guide in exchange for a mobile number, a form on your site, a sign-up sheet at a seminar, a QR code on a printed brochure. Each route needs a consent statement and a source tag, so you know later which one produced the people who buy.
Before you start
- Lead forms built under Sites, each with a separate, unticked text consent checkbox and plain wording.
- A source tag or hidden field for each route, such as paid social, website, seminar or brochure.
- A sending number enabled for SMS and, for American mobiles, carrier registration that covers marketing.
- A clear idea of what an advertising text should lead to: a booking, a payment or a reply.
- A way to see each contact's source on the record, such as the hidden field above.
How to set it up
Build one form per acquisition route under Sites, each with the text consent checkbox and a hidden field that stores the route name. Then welcome every new opted-in contact with a short text, so the first message they get confirms what they agreed to.
- Go to Automation > Workflows.
- Create a new workflow or open an existing one.
- Choose the Form Submitted trigger, filtered to the form.
- Add the Send SMS action.
- Enter a welcome confirming what they signed up for.
- Add personalisation or reusable content where it fits.
- Add Wait steps, conditions or other actions as needed.
- Test the workflow and the SMS content.
- Publish the workflow when it is ready to run.
Advertising texts then go to a smart list of opted-in contacts as bulk SMS, each with one offer, one trigger link and the opt-out wording. Split the list by source if you want to compare routes, and after a week compare clicks, bookings and revenue by source.
Where the opted-in audience comes from
For agencies, the usual route is a gated resource: a benchmark report or a checklist, delivered by text as well as email. For consultants, it is a seminar or webinar, where the reminder by text is the reason people give their mobile. For mortgage brokers, it is a rate-change alert that the client actively wants. For real estate firms, it is new-listing alerts for a defined area and price band.
What these have in common is a reason to give a mobile number that serves the contact, not just you. If the only reason is that your form makes the field mandatory, expect fake numbers and complaints. Keep the field optional and explain what you will send.
Suppose the agency runs a lead ad offering a quarterly benchmark report and collects 900 leads over three months, of whom 380 tick the text consent box. A single text offering a free audit slot goes to those 380. If it drew 64 clicks and 21 bookings on £4,500 of illustrative ad spend, the cost per opted-in contact would be about £12, and every later text to that audience would cost pennies. The numbers are hypothetical.
Measuring what each text produces
Attribution for text is easier than for most channels, because each message goes to known contacts and every click on a trigger link is logged against a named person. Measure three things per send: clicks, the action you wanted, such as bookings, and opt-outs. Then measure value further down: which contacts became opportunities, and which opportunities closed.
Compare the routes too. If seminar sign-ups book at twice the rate of paid social leads, move budget towards seminars, even if the cost per sign-up is higher. Read the SMS lead generation guide for more on the acquisition side.
The thing most articles get wrong
Most guides treat text advertising like a cheaper email blast and count success in messages sent. That measure rewards the wrong behaviour. Every text you send to an audience spends some of its goodwill, and the goodwill is what you paid to acquire. Measure revenue per opted-in contact over a year instead. It will tell you whether you are building an asset or slowly using it up.
Bundling text consent into general terms or a pre-ticked box. It looks efficient and makes the consent worthless if anyone challenges it. Keep a separate, unticked box with wording that names text messages.
What it replaces and the time it takes
For many firms, text advertising replaces repeated paid retargeting to people who have already engaged. Once someone has opted in, reaching them again by text costs little. Running the channel takes a few hours a month: writing two or three texts, checking the source reports and adjusting forms. Building the forms, workflows and tagging the first time takes a day.
When not to use it
Do not use text advertising for audiences that would never want marketing on their personal phone, such as senior buyers at large corporates who only engage by email. Do not use it for content that needs explaining. For the differences between ads and promotions, see SMS ads and text message promotions. For a broader view of the channel, read text message marketing.
Troubleshooting
Opt-in rates on forms are very low
The consent wording may be vague or the benefit unclear. Say exactly what you will send and how often, and test a version that offers something specific by text.
Source tags are missing on new contacts
The hidden field is not being filled, often because the form is embedded on a page that strips URL parameters. Set the field value directly on each form instead of reading it from the URL.
Clicks are high but bookings are low
The landing page is not matching the text. Make the page repeat the offer from the message, with the booking calendar visible without scrolling.
Complaints after the first text
People did not expect it. Send the welcome text immediately after opt-in, so the first message they receive is the one they asked for.
Frequently asked questions
Can I buy a list of mobile numbers to advertise to?
You should not. Bought numbers have no valid consent for your firm, and texting them breaks the rules in the US, the UK and most other markets.
Is text advertising worth it for B2B firms?
It works when the contact has a personal reason to want your texts, such as event reminders or alerts. It works poorly as a general promotional channel for corporate buyers.
How many advertising texts a month is reasonable?
Start with one or two and watch opt-outs. If they rise after a send, slow down.
Do I need a short code?
No. Most firms advertise from a standard long number, which also lets contacts reply.