They were leveraging enticing promotional sweepstakes as a way to drive email activation from customers who had not previously provided email addresses.  Clearly, they understand the communications savings of the email channel and current customer marketing trends in this area.   Take a look below, according to a recent industry channel preference white paper, over 70% of consumers would prefer the email channel for communications from companies they have granted permission to send ongoing communications:

Customer preferences are continuing to evolve … becoming more understanding when email communications is the most effective for their lives.  Clearly, marketers understand the cost efficiencies and speed of the communications.

For marketers, the use of a well designed sweepstakes can be a great way to increase your customer email coverage … ultimately allowing you to lower your customer communications costs and speed to market.