Zong have placed this deal to attract users. To win you would have to register yourself with zong.com.pk to become Official Testing Partner.
After paying for the initial bidding money of launch of 3G/4G spectrum Zong is giving away the initial 3G trials in selected locations only.
Like Ufone Telenor and Mobilink, Zong is also giving this service free. This will be available within this week. 4G testing service still requires some further time so it is not launching it right now.
After the launch of 3G they will be going to give 4G service to its customers. As the 4G requires some more time so Zong is initially giving 3G like other companies.