Fill in your details and upload a pic of your Student ID. We'll add 500MB of monthly data, as well as unlimited calling to Spark mobiles and landlines. All for FREE! Just check you're on our $19 Music Pack or one of our $19 or $29 Prepaid Value Packs first.
Not a bad way to boost a $19 plan to 1GB Data(plus WiFi) with 100 minutes(outside the Spark network).
You can also get a $20 credit for moving to Spark(paying $19-29 for the first month of the plan(Free SIM + delivery) before July 31st)
http://www.spark.co.nz/onlinedeals/