Win a Free Challenge

[S1lent]

Greetings,
If you can identify where and how I received the Free Knee Pad you will win a free challenge of your choice.  

Stipulations:  
1.  My second account need to be reactivated and my 1600 Gems restored.  (This is the account I am dumping.)
2.  Challenge value up to and including 128 Gems for 1st person to identify. (1 Each)
3.  Challenge value up to and including 40 Gems for 2nd person to identify. (1 Each)
4.  Challenge value up to and including 20 Gems for 3rd, 4th and 5th person to identify. (3 Each)
5.  Challenge value up to and including 16 Gems for 6th thru 10th person to identify.  (5 Each)
Total Gems 308.

Just PM me with your answer.  You will need to let me know how to get you the challenge.
Hints may be coming.

Good luck
Silent aka Mex

[S1lent]

Hint,
It was a promotion started a long time ago circa August 2009 and we could win prized.  One of the prized was a 3 Month membership to POGO.  What was the name?

Additionally, My second account has been reinstated and ready to award you the challenges.

Good luck
S1lent aka Mexikan0