When you win a free SKR contest, the amount of SKR you have won will be deposited into your "Promotions" account.
To access this, click on your balance on the header of the website and it will display your current "Available SKR" amount and "Promotion SKR" amount. Or you can visit your eWallet and click on the "Promotion" tab to view your balance and transactions.
Promotion SKR works exactly the same way as Available SKR, you can still use it to purchase marketplace items and do everything you can do with Available SKR. The only things you can't do with the Promotion SKR is withdraw it or sell it.
For any marketplace purchases or pay to enter contests, the money will be withdrawn from your Promotion SKR account before your Available SKR account.
This is done so we can differentiate between the free to play/promotional contests and the pay to play contests/SKR betting.