NEW YORK: Starbucks, the coffee house chain, is tapping the commercial potential of Twitter in a move that enables its customers to use the social network to send $5 gift cards to their friends.

The "tweet-a-coffee" program, which requires both sender and recipient to have Starbucks and Twitter accounts, delivers vouchers that can be redeemed immediately in-store, either in printed form, or via a mobile screen or via transfer to a Starbucks mobile app.

According to Adam Brontman, Starbucks Chief Digital Officer, the initiative is designed to prompt spontaneous gifting via the micro-blogging site.

"What's so exciting about extending our eGifting platform to Twitter is the open and real time nature of the platform. Tweet-a-coffee allows us to do something quite different in eGifting in that people can now give the gift of Starbucks to anyone on Twitter in the moment," he explained.

It also indicates a wider trend of how large brands are formulating new ways of engaging consumers and driving sales via Twitter.

"We view it as the first step toward many things we can do with Twitter that are commerce related," said Brontman. "It just feels more conversational; it feels more authentic; and it feels more in the flow of how we're actually using digital."

Earlier this year, American Express, the credit card provider, launched a service for its customers to be able to shop for certain items on Twitter and pay by tweeting purchase hashtags.

Once shoppers retweet the confirmation tweet from Amex within 15 minutes of receiving it, products are shipped to the account billing address synced with Twitter, and payment taken from the synced Amex account.

Data sourced from Forbes and Fast Company; additional content by Warc staff