The delivery method for each reward is located in the reward's description when you redeem. Most rewards are instantly ready to use in your Shopkick profile (though can sometimes take a few hours to process depending on shopkicker traffic). Some rewards are emailed to you. A few will be snail-mailed or require you to use a special code and redeem online. Be sure to read the info on the reward for delivery or steps you need to take to redeem your reward.