From April 6 through April 27, you'll earn Woo Bucks on any Darphin purchase! How it works... For all the Darphin products you purchase, we give you 10% back on a Woo Bucks gift card redeemable in May (on any product). Spend $200 on Darphin products April 6-27, for example, and you'll get a $20 Woo Bucks card to use in May on any Woo purchase.