50 INTRODUCTION OUR BUSINESS OUR MATERIAL TOPICS STAKEHOLDER ENGAGEMENT 2018 SUSTAINABLE BUSINESS REPORT Artwork from the Shinda Mamili campaign that incentivised customers to purchase Tunukiwa offers (bundles) by entering them into regional prize draws. FLEX allows users to convert prepaid units into airtime, SMS or data as needed. Voice biometrics introduced In December 2017, we launched a new voice biometric authentication service, known as Jitambulishe . An industry first in Kenya, the innovative service allows customers to record a ‘voiceprint’ that can be used to identify them in the future. Once their voiceprint has been captured, customers can identify themselves by saying “at Safaricom, my voice is my password” when they call our customer service lines. As well as cutting down the authentication steps required before customers can be assisted with services like resetting M-PESA PINs and PUK requests, Jitambulishe is expected to help us reduce fraud and identity theft because voiceprints are extremely hard to falsify, and customers will no longer need to divulge sensitive security information to third parties. Over 463,000 customers have successfully enrolled on Jitambulishe and it has also increased the scope and efficiency of our Interactive Voice Recognition (IVR) service, allowing us to introduce eight additional self-service options and serve a daily average of 52,000 customers.