How to leverage free marketing SMS to increase return visits

Welcome to this briefing from Purple. Today we are covering one of the most underused assets sitting inside your venue right now - your Guest WiFi network - and specifically, how to use it to run free marketing SMS campaigns that bring visitors back through your doors. Let me set the scene. You have a hotel, a retail chain, a stadium, or a conference centre. Every day, hundreds or thousands of people connect to your WiFi. They hand over their phone number to authenticate. And then they leave. Most operators do nothing with that data. That is a significant missed opportunity. SMS marketing achieves a 98% open rate. Email sits at around 22%. Click-through rates for SMS run between 18 and 35 percent, compared to roughly 3 percent for email. And ROI estimates place SMS returns at between 21 and 41 pounds for every pound spent, with peak campaigns reaching 71 pounds per pound. These are not marginal gains. This is a fundamentally different channel. So let us talk about the architecture. When a guest connects to your WiFi through Purple's captive portal, they authenticate using their mobile number. Purple verifies that number in real time via a one-time passcode. At the same moment, if the guest opts in to marketing communications, that verified phone number flows directly into Purple Engage - our CRM and campaign automation layer. No manual export. No third-party data broker. First-party, verified, consented data, captured at the point of access. This matters enormously from a compliance standpoint. Under GDPR and the UK's Privacy and Electronic Communications Regulations - PECR - you need explicit, freely given consent to send marketing SMS. The key word there is freely given. You cannot make WiFi access conditional on marketing consent. Purple's captive portal separates the two: guests get WiFi regardless, and the marketing opt-in is a separate, clearly labelled conscious choice. That is the architecture that keeps you on the right side of the ICO. In the United States, the Telephone Consumer Protection Act - TCPA - requires prior express written consent before you send any automated marketing text. Purple's opt-in flow captures and timestamps that consent, creating an auditable record. This is not just good practice. It is a legal requirement, and the fines for non-compliance run into millions of dollars. Now let us get into the implementation detail. Purple Engage supports three core SMS journey types. First, the welcome journey. A guest connects to your WiFi, opts in, and within minutes receives a personalised welcome message. For a hotel, that might be a room upgrade offer. For a retailer, it could be a ten percent discount valid today only. For a stadium, it might be a fast-track entry code for their next visit. This immediate touchpoint has the highest engagement rates of any SMS type - because the guest is physically in your venue right now, and the message is contextually relevant. Second, the re-engagement journey. Seven days after their visit, Purple Engage automatically sends a follow-up message. At this point, the guest has had time to reflect on their experience. A well-timed message with a specific incentive - say, a limited-time offer or an event announcement - converts at rates between 21 and 30 percent according to Sakari's 2025 benchmarks. The key is specificity. Generic messages underperform. Messages tied to the guest's actual visit - the venue they attended, the day they were there - perform significantly better. Third, the win-back journey. Thirty days of no return visit triggers a win-back SMS. This is your last automated touchpoint before a guest becomes dormant. The message should carry your strongest offer. Purple's analytics layer tells you which guests are at risk of lapsing, so you can segment this audience and tailor the message accordingly. Let me give you two concrete examples. The first is a mid-scale hotel group with 40 properties. They deployed Purple Engage across their estate, running on Cisco Meraki access points. Within 90 days, they had captured verified mobile numbers from 68 percent of WiFi-connected guests who opted in. Their seven-day re-engagement SMS campaign achieved a 24 percent return visit rate among the contacted group, compared to 9 percent for the control group who received no message. That is a 15 percentage point uplift, directly attributable to a single automated SMS journey. The incremental revenue per property averaged 4,200 pounds per month. The second example is a retail chain with 120 stores. They integrated Purple Engage with their existing loyalty programme via Purple's API. Shoppers who connected to in-store WiFi and opted in received a personalised SMS 48 hours after their visit, referencing the specific store they visited and including a time-limited voucher. The campaign ran for six months. Average basket size among SMS recipients was 18 percent higher than the non-contacted group. Opt-out rates stayed below 1.5 percent throughout, well within the industry benchmark of 3.5 percent. Now, the pitfalls. The number one failure mode is frequency. Sending more than two messages per month to the same contact is the fastest way to drive opt-outs. Fifty-three percent of SMS unsubscribes are caused by over-frequency, according to Sakari's consumer research. Set hard frequency caps in your campaign settings. Purple Engage enforces these automatically, but you need to configure them correctly at setup. The second pitfall is irrelevance. A guest who visited your Edinburgh venue does not want a message about your London opening. Segment your audience by location, visit recency, and visit frequency before you send anything. Purple's analytics layer gives you all three dimensions out of the box. The third pitfall is timing. Do not send SMS messages between 9pm and 8am. This is a legal requirement under PECR in the UK and a strong best practice globally. Purple Engage includes send-time optimisation that automatically schedules messages within compliant windows, factoring in the recipient's local time zone. Now for the rapid-fire questions I hear most often from clients. Can I run SMS campaigns without a separate SMS platform? Yes. Purple Engage includes SMS sending as part of the Engage plan. You do not need a separate contract with an SMS gateway provider. The sending infrastructure is built in. What hardware does this work with? Purple is hardware-agnostic. The captive portal and data capture layer works across Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme, and Fortinet. If you have a mixed estate, that is fine. How do I measure ROI? Purple Engage tracks SMS delivery, click-through rates via unique short links, and return visit attribution using WiFi reconnection data. When a guest who received an SMS reconnects to your WiFi within a defined window, Purple logs that as an attributed return visit. This gives you a direct line between campaign spend and footfall. Is this genuinely free? The SMS sending credits are included in the Engage plan. There is no per-message charge on top of your Purple subscription. That is what we mean by free marketing SMS - the marginal cost of sending an additional message is zero. To summarise. Your Guest WiFi network is already capturing verified mobile numbers at scale. Purple Engage automates three SMS journeys - welcome, re-engagement, and win-back - that convert those numbers into return visits. The compliance framework is built in, covering GDPR, PECR, and TCPA. The hardware integration covers all major enterprise access point vendors. And the analytics layer closes the loop between campaign activity and footfall. The next step is straightforward. If you are already on Purple Connect or Capture, speak to your account manager about upgrading to Engage. If you are new to Purple, visit purple.ai to see how 80,000 venues are already using Guest WiFi as a first-party data and marketing channel. Thank you for your time. This has been a Purple technical briefing on free marketing SMS and return visit optimisation.