From Verizon’s iPhone FAQ:

Current Verizon customers who purchased and activated new smartphones, feature phones or certified pre-owned phones between 11/26/2010, and 01/10/2011, are eligible to receive up to a $200 Visa debit card when they purchase an iPhone 4 at full retail price by 02/28/2011 and return their existing phone.

(Via Boy Genius Report)