Barnes & Noble: http://www.barnesandnoble.com/u/NOOK-Book-App-Gifts-FAQ-Questions/379003362/
Giving a digital gift is quick and easy - we call it eGifting! NOOK Books and NOOK Apps can be eGifted to anyone with a valid email address. You do not need a NOOK to purchase a digital gift.
To eGift a NOOK Book or NOOK App, click the "Buy as Gift" link under the "Buy Now" button on the product page. You will have the opportunity to enter your gift recipient's email address and an optional gift message. You may preview the eGift email before purchasing. When you are ready to place your order, just click the "Buy Now" button.
You have the option to select a date that you would like the eGift email to be delivered. You may set the delivery date up to one year from the date you place your order. The email will be sent to your gift recipient's inbox in the early morning hours on the date you selected.
- Sign in to the iTunes Store with your Apple ID.
- Find an item in the App Store or iTunes Store that you want to gift.
- Click the arrow to the right of the price and select Gift This.
- Type the email address for the person you want to send the iTunes Gift.
- If you like, add a message.
- Pick the day you want to send the gift and click Next.
- Do I have to own a Kindle to give or receive a Kindle book as a gift? No. Kindle books can be given and received by anyone with an e-mail address. Kindle books can be read either on Kindle or using one of our free reading apps.
- What if the recipient doesn't like or want their gift? Kindle books received as gifts can be exchanged for Amazon.com gift cards.