People who make donations on JustGiving pages after being prompted on Twitter are nearly twice as generous as those who are inspired to give by a Facebook prompt, according to new figures.

In a study on the average gift value of donors directed to JustGiving pages via social media, Twitter prompts came out on top, with an average gift from someone coming from a Twitter link worth £30.26, compared with just £18.33 on Facebook. Facebook, however, remains the vastly more popular social network for JustGiving donors, accounting for 97 per cent of all visits directed through a social media source - in contrast Twitter facilitates a tiny 1 per cent of all visits from social media sources.

JustGiving predicts that by 2015 half of all its traffic will come from Facebook. Last September Facebook drove 27 per cent of all traffic to the online donation platform, a 130 per cent increase on the previous year.

In the donation value stakes, however, YouTube came in a close second to Twitter, with an average gift value of £28.77 followed by LinkedIn, from which donors gave an average gift of £25.21.

Head of insight at JustGiving, Elizabeth Kessick, said: “Third sector organisations should ignore social media at their peril as this data shows that social giving is an increasingly important driver for donations. The good news is that it’s also a very cost-effective way for charities to canvass for support.”

The importance of investing time and resource in digital media as a whole was emphasised last week at a conference held by the Media Trust. Media Trust chief executive Caroline Diehl said that funders need to begin investing in charities’ digital media capabilities.

“Funders don’t like to invest in something that might fail, but charities and communities need to be given the chance to invest in developing new skills before they can experiment and innovate,” said Diehl. “Charitable funders need to make a step-change, invest more in digital media and be less afraid of trying new things.”

JustGiving has now launched a Facebook app, which allows donors to give to a JustGiving page without leaving the social media site. 

Interested in social media and digital media for fundraising? Check out the cracking programme for next week’s Mobile and Digital Conference 2011 produced by Fundraising magazine.