USSD is an interactive, session-based application with immediate connection and delivery. The *130*1313# number is a free service number. Users register with their cellphone, select the network, the amount and make the purchase. An sms with the voucher number will be sent to the phone which can then be used as normal for the top-up. Or, foward the sms on to another user. It is a safe and secure system that verifies all data. SWAP developed its own WASP (Wireless Application Service Provider) as part of their own technical network that can handle all the demands of the mobile market. For more information, visit www.swapmobile.co.za.