You start the process ahead of the friend's birthday by going to Amazon's site. After logging into your Amazon and Facebook accounts and connecting the two -- which allows Amazon to collect information about you and your friends -- you'll be shown a list of your friends with birthdays in coming days.
You can then click "start a gift," which allows you to write a birthday message and select the gift card amount. The total can be $1, $5, $10, or $25, and for a limited time, users can get a $3 credit from Amazon.
After you select the total, you're allowed to preview the message that will be delivered to your friend's Facebook timeline on his or her birthday. You can then select mutual friends to contribute to the gift. On the actual birthday, the many individual birthday messages will appear on the person's timeline along with links to claim the gift.
Gift giving through social media has been picking up steam over the past year. Facebook in late 2012 launched Facebook Gifts to allow users to send presents to their friends via the social networking site. Of all the products that Facebook unveiled last year -- and there were many as the company amped up its efforts to make more money off its billion-plus users -- Gifts is one of the biggies, certainly in terms of potential.