Lucky? Spend 50cents and get 10dollar FREE?

As usual, constantly opened my Gmail from time to time...
Saw this...
opps, low res, click on it to look clearly ba. It's "Lunch on us weekly draw winner...Congratulations! You are one of the 5 winners..." Lunch on us, with who? With VIP? Just couldn't remember when did i participate in any contest in recent months. until I open it...
"
Dear HO WENG FEI

Congratulations! You are one of the 5 lucky winners of our NTU Lunch on Us Weekly Draw.

We will send you an official letter for prize collection, in the meantime, please log on to www.ezrewards.com.sg to make sure that your contact details are correct. To collect your prize of $10 top-up into your ez-link card, please take note of the following:
o Bring along the official letter and
o Your Identification card to the branch of 7 Eleven in NTU campus

Please note that you have to claim your prize by 15 June 2008.

Thank you for paying with ez-link cards and participating in this draw, we hope to have your continuous support.

ez-Rewards "

Oh i see. Signed up for my ezlink via www.ezrewards.com.sg last month and by using your ez-link card in NTU new canteen outlets & 7-11, you are eligible to participate in this lucky draw...but the thing is, I just use the card Once on 50cents orange juice only woh, am I really lucky to get $10 ezlink top up free to so-call subsidize my bus fare to-and-fro NTU and my IA company Sony, or is it not much people know about this promotion?

Anyone knows? Have you register your ezlink card?