12 February 2013 Last updated at 07:32 ET

American Express launches purchase-via-Twitter service

The new scheme builds on Amex's existing Twitter-based promotions

American Express (Amex) has launched a purchase-by-tweet service for its US-based customers.

Credit-card holders post a specific hashtag on Twitter to trigger payments from their accounts.

Products from Amazon, Sony and Microsoft are being offered at a discount to entice shoppers to use the new service.

However, one retail expert dismissed the initiative as a "gimmick" that was unlikely to catch on.

This is not Amex's first tie-up with social media.

It already operates a voucher-free discount scheme with Foursquare - a location-based network - in the UK and US.

It has also offered savings to users who tweet promoted hashtags - such as #AmexWarby - listed on its Twitter account.

An Amex spokesman was unable to provide any detail of when it might extend the latest scheme to other countries.

Confirmation hashtags

Amex members wishing to use the purchase-by-tweet facility must first link their card to their Twitter account via the financial services firm's app.

They then need to go to the firm's Twitter page and select the Favourites section to view which items are on sale and the associated hashtags.

Then, after sending an initial tweet to start the sales process, they must wait for a confirmation message from the @AmexSync account.

This contains another hashtag that must be posted in a fresh tweet by the user within 15 minutes to make the sale to go through.

Users are warned that products may sell out, voiding the process, and that they can only buy one of each item.

Amex's senior vice president for digital partnerships, Leslie Berland, said that the success of the firm's existing social media schemes suggested that there was "significant power in combining our assets with Twitter's platform".

However, Bryan Roberts, director of retail insight at consultants Kantar Retail, was more sceptical about its chances.

"It seems to be technology for technology's sake," he told the BBC.

"The advances in payment technology that are going to win in the long run are the ones that make shoppers' lives easier or quicker.

"This seems to tick neither box, so it's a nice marketing gimmick but it won't go much beyond that."