How to leverage SMS marketing best practices to increase return visits
This guide details how venue operators can use SMS marketing to drive measurable return visits by capturing verified first-party phone data via Guest WiFi. It covers technical architecture, compliance frameworks, segmentation strategies, and real-world deployment scenarios.
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Executive Summary
SMS marketing represents a significant untapped revenue channel for physical venues. While most IT and marketing teams understand the value of email, SMS offers a 98% open rate and a 45% response rate [1]. The challenge is not the medium itself, but the data capture mechanism. This guide outlines how to use Guest WiFi infrastructure to capture verified, consented phone numbers and automate targeted SMS campaigns that increase return visits. We detail the technical deployment of Purple Engage across enterprise hardware, the compliance requirements for GDPR and TCPA, and the architectural decisions required to build a scalable SMS programme.
Technical Deep-Dive
The foundation of an effective SMS programme is the data capture layer. Relying on point-of-sale systems or loyalty app downloads introduces significant friction. Guest WiFi, however, is a high-demand utility that visitors actively seek out.
When a guest connects to the network (supported across Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme, and Fortinet hardware), the controller redirects them to a captive portal hosted by Purple. This portal presents a form requesting a mobile number and explicit marketing consent.

Once the guest submits the form, Purple authenticates the device MAC address via RADIUS and grants network access. Concurrently, Purple Engage stores the verified phone number, timestamps the consent, and enriches the profile with behavioural data (dwell time, visit frequency, location data). This first-party data is then available for automated campaign triggers via API or direct integration with identity providers like Microsoft Entra ID, Okta, and Google Workspace.
Compliance Architecture
Consent must be explicit. Under GDPR and PECR in the UK, and TCPA in the US, pre-ticked boxes or bundled terms and conditions are non-compliant. Purple Engage enforces a strict opt-in architecture. The consent checkbox is unticked by default, clearly labelled, and distinct from the network access terms.
Furthermore, the system automatically appends opt-out instructions (e.g., 'Text STOP to opt out') to every outbound message and processes opt-out requests immediately, updating the CRM record to prevent future sends.
Implementation Guide
Deploying an automated SMS programme requires coordination between IT and marketing. Follow these steps for a secure, compliant rollout.
- Configure the Captive Portal: Set up the Purple splash page to request a mobile number. Ensure the SMS marketing consent checkbox is visible, unticked, and clearly worded.
- Define the Audience Segments: Use Purple's analytics to create segments based on visit behaviour. For example, create a segment for 'First-time visitors who dwelled for over 60 minutes'.
- Establish the Triggers: Configure automated workflows in Purple Engage. A common trigger is '24 hours after a guest disconnects from the network'.
- Draft the Messages: Keep messages under 160 characters. Identify the brand immediately, state the offer clearly, include a single link, and append the mandatory opt-out instruction.
- Monitor and Iterate: Launch the campaign to a small test segment. Monitor the opt-out rate and click-through rate before scaling to the full database.
Best Practices
To maximise the effectiveness of your SMS marketing strategy, adhere to these proven industry practices.
- Maintain strict data hygiene: Remove numbers that bounce or fail to engage over a 90-day period to protect your sender reputation.
- Respect quiet hours: Do not send promotional messages before 08:00 or after 21:00 in the recipient's local time zone.
- Segment ruthlessly: Broadcast messages yield poor results. Segment by visit recency, frequency, and location to ensure relevance.
- Integrate channels: SMS should complement, not replace, email. Use SMS for urgent, high-value offers and email for detailed content.

Troubleshooting & Risk Mitigation
- High Opt-Out Rates: If your unsubscribe rate exceeds 2%, your messages are likely too frequent or irrelevant. Review your segmentation logic and reduce send frequency.
- Carrier Filtering: Mobile carriers actively block unregistered application-to-person (A2P) traffic. In the US, ensure your brand and campaigns are registered via the 10DLC system. In the UK, register your Sender ID to prevent spoofing.
- Low Conversion: If click-through rates are high but conversions are low, the landing page is likely the issue. Ensure the destination URL is mobile-optimised and the offer matches the SMS copy.
ROI & Business Impact
A well-structured SMS programme delivers measurable returns. Track the opt-in rate at the Captive Portal, the click-through rate of outbound messages, and the conversion rate of those clicks into return visits or direct revenue. Purple's analytics dashboard provides visibility into these metrics. Venues typically see a return of £21 to £71 for every £1 spent on SMS marketing [2], driven by the immediacy of the channel and the high intent of the verified audience.
Listen to the full technical briefing on SMS marketing architecture below:
References
[1] Falkon SMS, "SMS Marketing Statistics 2026: Open Rates, ROI & Engagement Data", 2026. [2] Upcity, "SMS Marketing Survey 2023", 2023.
Key Definitions
Captive Portal
A web page that a user of a public-access network is obliged to view and interact with before access is granted.
The primary mechanism for capturing first-party data and marketing consent on a Guest WiFi network.
First-Party Data
Information a company collects directly from its customers and owns entirely.
Crucial for building a compliant SMS database, as opposed to purchasing third-party lists which carry high regulatory risk.
10DLC (10-Digit Long Code)
A system in the US that requires businesses to register their brand and campaigns before sending A2P messages from standard local phone numbers.
Failure to register results in carrier filtering and blocked messages, directly impacting campaign ROI.
A2P (Application-to-Person) Messaging
The process of sending SMS messages from an application to a mobile user, typically used for marketing or alerts.
Carriers heavily regulate A2P traffic to prevent spam, requiring strict adherence to opt-in and opt-out protocols.
PECR (Privacy and Electronic Communications Regulations)
UK regulations that sit alongside GDPR, specifically governing electronic marketing, including SMS.
PECR dictates that organisations must have prior consent before sending marketing texts to individuals.
TCPA (Telephone Consumer Protection Act)
US federal law restricting telemarketing calls and the use of automated telephone equipment, including SMS.
Violations of the TCPA can result in fines of up to $1,500 per message, making strict opt-in compliance essential.
RADIUS (Remote Authentication Dial-In User Service)
A networking protocol that provides centralised Authentication, Authorization, and Accounting management for users who connect and use a network service.
Used by Purple to authenticate devices based on MAC address after the captive portal flow is completed.
Double Opt-In
A process where a user signs up and then must confirm their subscription via a follow-up message (e.g., replying YES).
Provides the strongest evidence of consent and results in a highly engaged list, though it introduces friction at signup.
Worked Examples
A 200-room hotel needs to reduce reliance on Online Travel Agencies (OTAs) and drive direct bookings from previous guests. They currently capture email addresses at check-in but see low open rates.
The hotel deploys Purple Engage on their existing WiFi network. They configure the captive portal to capture mobile numbers and SMS consent. They build an automated workflow that triggers a message to guests on the day of checkout: 'Thanks for staying with us. Enjoy 15% off your next direct booking: [link]. Text STOP to opt out.'
A fashion retailer with 40 locations wants to increase footfall during quiet mid-week periods. They have a large database of phone numbers but no visibility into store-level visit patterns.
The retailer integrates their WiFi hardware with Purple to capture MAC addresses and associate them with verified phone numbers. They create a segment of shoppers who have visited a specific store on a weekend but not during the week. They send a targeted SMS on a Tuesday morning: 'Quiet Tuesday? Visit us in-store today for an exclusive mid-week offer: [link]. Text STOP to opt out.'
Practice Questions
Q1. A stadium operator wants to text all 50,000 attendees a merchandise discount code during the half-time break. They plan to use the phone numbers captured during ticket sales. What is the primary risk?
Hint: Consider the difference between transactional data collection and marketing consent.
View model answer
The primary risk is a compliance violation under GDPR/PECR or TCPA. Phone numbers collected for ticketing are transactional. Unless the attendees explicitly opted in to receive marketing SMS during the ticket purchase process, sending a promotional text is illegal. The operator should instead use the stadium Guest WiFi to capture explicit marketing consent from attendees on-site.
Q2. Your marketing team reports that the SMS unsubscribe rate has spiked to 4.5% following a recent campaign promoting a new menu at your restaurant chain. What is the most likely cause and immediate action required?
Hint: Review the 'Troubleshooting & Risk Mitigation' section regarding high opt-out rates.
View model answer
An unsubscribe rate above 2% indicates the messages are either too frequent or irrelevant to the audience. The immediate action is to pause the campaign, review the segmentation logic, and ensure the offer is targeted correctly (e.g., not sending a steak offer to known vegetarian diners). The team should also reduce the overall frequency of messages.
Q3. You are deploying Purple Engage across a university campus to communicate with students. The IT director insists that the SMS consent checkbox on the WiFi splash page must be pre-ticked to maximise the database size. How do you respond?
Hint: Refer to the 'Compliance Architecture' requirements for valid consent.
View model answer
You must advise the IT director that a pre-ticked checkbox is non-compliant with privacy regulations (GDPR/PECR/TCPA). Consent must be a conscious, unambiguous choice. While an unticked box will result in a smaller database, it ensures legal compliance and creates a more engaged audience, ultimately delivering better campaign ROI and protecting the university from significant fines.