Sony Entertainment Network

Edit: Did some searching and it looks like its AU only, when i tried to go to same promotion page on UK version of SEN I got an Error but double check anyway.

Not sure if this is UK/EU also although the banner i saw on PSN had a Euro sign instead of dollar anyway.
I know its up for Australian store.
Basically if you top up your PS wallet with 50 dollars you get emailed a 10 dollar voucher from sony. Should be valid until the 30th of april and voucher lasts till may also.

"Note that the Top-Up need not be performed in a single SEN wallet top-up but may be performed in a number of top-ups during the Promotional Period."
The voucher can be redeemed anytime until May 31st.