In December last year, Twitter expanded its pro-bono ads program, and changed its name to Twitter Ads for Good, unveiling a new fund designated for non-profits in the company’s hometown of San Francisco.

With that in mind, Twitter is now pledging its support to The American Red Cross over the festive period, by donating $1 in Twitter Ads for Good to @RedCross with each #Tweet4Good-hashtagged tweet.

This will run all the way up to December 31, though the social network has capped its donations at a $20,000 limit.

Twitter has helped pair up celebrities and charities to build a megaphone of social good, serving up free advertising to cash-strapped nonprofits to get support for cleaner water, those dealing with cancer, among other good causes. Indeed, until its Ads for Good initiative last year, Twitter had helped a number of organizations get attention, although not officially, through promoted tweets and the likes.

Now, The American Red Cross will receive $20,000 (assuming 20,000 of you good folks tweet the hashtag) to build their Twitter presence and help spread the good word.

You can actually see who’s tweeting with the hashtag already, on this dedicated Tweet4Good landing page: