How to leverage advantages of SMS marketing to increase return visits

Welcome to this executive briefing from Purple. I'm going to walk you through one of the most practical, high-return strategies available to venue operators right now: using the advantages of SMS marketing, fuelled by first-party data from your Guest WiFi, to drive measurable increases in return visits. If you manage a hotel estate, a retail chain, a stadium, or a conference centre, this is directly relevant to you. We'll cover the technical architecture, the compliance requirements, the segmentation strategies that actually move the needle, and the ROI you can expect. Let's get into it. First, the context. Most venues already have enterprise-grade WiFi hardware deployed. Cisco Meraki, HPE Aruba, Ruckus - the infrastructure is there. But in the majority of cases, that network is a cost centre. It provides connectivity, and that's it. The commercial value of the data flowing through it goes completely untapped. The shift happens when you introduce a captive portal with a phone number capture field and an explicit SMS opt-in. Suddenly, every WiFi login becomes a first-party data event. You're building a verified CRM database from your existing infrastructure, with no additional hardware required. Now, why SMS specifically? The numbers are stark. SMS achieves a 98% open rate, compared to email's 20%. Ninety percent of messages are read within three minutes of delivery. The click-through rate for SMS sits at around 18%, versus email's 2.5%. And the return on investment is between 21 and 41 pounds for every pound spent, according to Sakari and Emarsys benchmarks from 2025. These are not incremental improvements over email. They are a different order of magnitude. And when you combine that channel performance with the behavioural data you capture through Guest WiFi, you get something genuinely powerful: the ability to send the right message, to the right person, at the right moment. Let me walk you through the technical architecture. How does this actually work end to end? When a visitor connects to your Guest WiFi network, your wireless controller - whether that's Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, or any other enterprise hardware - redirects their traffic to a captive portal. Purple integrates with all of these via standard RADIUS authentication. On the captive portal, the visitor enters their phone number. Critically, they must also check an unticked box explicitly consenting to receive SMS marketing from you. This is not optional. Under GDPR Article 6(1)(a), consent must be freely given, specific, informed, and unambiguous. Pre-ticked boxes are not valid consent. Purple's portal enforces this by design. Once the visitor submits, Purple authenticates the device, grants internet access, and securely transmits the phone number, the device MAC address, the timestamp, and the venue location into Purple Engage - our CRM platform. Here's where identity resolution becomes important. Purple links that phone number to the MAC address. When that visitor returns to your venue - or visits another location within your estate - the network detects the MAC address passively. The visitor doesn't need to log in again. You're silently building a behavioural profile: visit frequency, dwell time, preferred locations, cross-venue movement. This is first-party data. You own it. No algorithm change, no third-party cookie deprecation, no platform policy update can take it away from you. Now let's talk about segmentation, because this is where most venues leave money on the table. The biggest mistake with SMS marketing is treating it like a broadcast channel. Sending the same message to your entire database on a Friday afternoon is how you generate opt-outs, not return visits. Research from SAP Engagement Cloud shows that 23% of consumers would stop supporting a brand if they felt spammed. The solution is behavioural segmentation. Because Purple Engage holds rich visit data, you can build precise audience segments. The first segment to build is the lapsed visitor campaign. Set a trigger: if a device MAC address has not been detected in your venue for 60 days, dispatch an automated SMS with a strong re-engagement offer. A 20% discount, a free upgrade, an exclusive event invitation. This is your win-back campaign, and it runs automatically without any manual intervention. The second is the real-time welcome campaign. When a known MAC address connects to your network, trigger an immediate SMS - valid only for the next two hours at your on-site cafe or restaurant. This is contextual marketing at its most effective. The visitor is physically present, the offer is time-limited, and the relevance is immediate. The third is the frequency-based loyalty campaign. Segment visitors who connect three or more times per month. These are your most valuable regulars. Send them early access to events, exclusive member pricing, or personalised recommendations based on their visit patterns. Each of these campaigns runs on automation. You configure the trigger, the audience criteria, and the message template in Purple Engage once. The platform handles the rest. Let me give you two concrete case studies that illustrate this in practice. The first is a 200-site retail chain. They already had Cisco Meraki access points deployed across all locations. They updated their captive portal to require a phone number and present an explicit SMS opt-in checkbox. Within 30 days, they had built a database of opted-in shoppers. They created a segment for visitors who connected between 9 and 11 in the morning, and scheduled a targeted SMS campaign to this segment every Monday, offering a 15% discount valid only before noon on weekdays. The result was a measurable increase in off-peak footfall, with a high redemption rate on the offer and a significant reduction in the cost per acquired visit compared to paid social advertising. The second case study is a large stadium operator with 40,000 fans connecting to WiFi simultaneously during events. They used HPE Aruba hardware and Purple to capture phone numbers at login. They segmented the audience by access point location - so they knew whether a fan was in the North Stand or the South Stand. Five minutes before half-time, they dispatched localised SMS offers. North Stand fans received a discount code for the North Concourse store. South Stand fans received one for the South Concourse. This prevented cross-stadium traffic, managed crowd flow efficiently, and drove a significant uplift in merchandise sales per event. Purple's platform data shows an average 24% increase in return visits for audiences engaged through automated SMS campaigns driven by Guest WiFi data. Across 80,000 live venues and 440 million logins in 2024, that's a consistent, repeatable outcome. Now, let me address the implementation pitfalls, because there are several that trip up even experienced teams. The first is MAC address randomisation. Modern iOS and Android devices use private MAC addresses by default. However, they typically use the same private MAC address consistently for a specific network SSID. So as long as the visitor connects to your specific Guest WiFi network, the tracking remains consistent for that venue. This is a known behaviour and Purple's platform accounts for it. The second pitfall is over-frequency. The data is clear: 53% of consumers unsubscribe from SMS lists because brands send too many messages. Limit promotional bulk SMS to no more than twice per week unless the message is triggered by real-time on-site behaviour. Triggered messages - welcome offers, half-time deals, post-visit follow-ups - can be sent more frequently because they are contextually relevant. The third pitfall is neglecting the opt-out workflow. Every SMS must include a clear opt-out instruction - typically "Reply STOP to unsubscribe." When a user replies STOP, your SMS gateway must update Purple Engage immediately, suppressing that number from all future campaigns. Purple handles this automatically, but you need to verify that your gateway integration is correctly configured before going live. The fourth pitfall is launching at scale before validating the data pipeline. Always pilot at a single venue first. Validate the RADIUS configuration, confirm phone numbers are flowing correctly into Purple Engage, test the opt-in checkbox rendering on mobile devices, and run one automated campaign end to end before rolling out across your estate. Let me close with a rapid-fire Q&A on the questions we hear most often. Does the captive portal slow down the login process? No. RADIUS authentication happens in milliseconds. The friction is the user typing their phone number. Keep the portal form to a single field on mobile and you'll see opt-in rates of 30% or higher. What about GDPR and TCPA compliance? Purple's portal enforces unticked opt-in checkboxes by design. All consent records are timestamped and stored in Purple Engage, providing an auditable trail. For TCPA compliance in the US, ensure your opt-in language explicitly states the nature of the messages and the frequency. Can we integrate SMS with our existing email CRM? Yes. Purple Engage integrates with major CRM platforms and marketing automation tools. Running SMS and email in parallel, with coordinated timing, delivers a 47.7% lift in customer engagement according to Omnisend data. What hardware do we need? None beyond what you already have. Purple is a cloud overlay. It works with Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme, and Fortinet. No hardware replacement required. To summarise. The advantages of SMS marketing for venue operators are clear: a 98% open rate, 90% of messages read within three minutes, and an ROI of between 21 and 41 pounds per pound spent. When fuelled by first-party data captured through Guest WiFi, SMS becomes a precision instrument rather than a broadcast channel. The architecture is straightforward: captive portal with phone number capture and explicit opt-in, RADIUS authentication via your existing hardware, identity resolution in Purple Engage, behavioural segmentation, and automated campaign dispatch. No custom app development. No hardware replacement. No third-party data dependency. Your next steps are three. First, align your IT and marketing teams on the portal configuration and consent language. Second, pilot at a single venue, validate the data flow, and run one automated campaign. Third, measure the opt-in rate and the return visit uplift, then scale across your estate. You already own the infrastructure. Purple makes it work harder for your business. For more on Purple Engage and Guest WiFi analytics, visit purple.ai. Thank you for listening.