The growth in appeals for texted donations over the past couple of years has been exponential. On pretty much every train you take into or out of London now, you'll be reminded how a donation of just a few pounds could achieve something extraordinary.
On my last journey, from Penge East to Victoria, I sat opposite two posters asking me to give by using my mobile - one asking for just £1 match-funding to provide a mosquito net to help save a child's life.
Some of the most impressive responses to text appeals have been for international development agencies after major disasters. Texting provides a quick and easy way for people to respond when they read in their morning newspapers about lives ripped apart.
The popularity of train advertising asking commuters to give by text has reached a point where KBH, the transport advertising company, believes it is necessary to limit adverts for charities to a maximum of 20 per cent of the total to avoid excessive competition between them.
Mobile traffic to the digital donation platform JustGiving overtook desktop traffic for the first time in April. Adapting to this shift, the company launched its 'one-touch' giving for mobiles in June, making giving on the move even easier.
JustGiving is now leading on text giving, as it did with online sponsorship during the early noughties. Once again, the company is offering its services for free as it establishes a new way of making donations.
JustTextGiving and other free text-to-give programmes, such as that run by MyDonate, have made receiving donations by text a realistic fundraising option for charities of all sizes. For now, at least, registered charities are able to get free text codes and posters, stickers and even free banners to support their efforts.
It would not make sense for every charity to run mass-media campaigns seeking texted donations. But there is scope, even for small charities, to experiment with building text into fundraising programmes - calling on people to donate using their mobile phones at events and including the text-to-give number on all materials.
There are drawbacks to donations by text: they tend to be small and many text donors prefer to remain anonymous, limiting the scope for relationship building. But there is potential for generating regular repeat SMS donations, and charities are using mobile numbers generated by small donation campaigns to make follow-up thank-you calls and to provide the opportunity for donors to set up direct debits.
For many charities, it will take trial and error to maximise the potential of giving by text and to work out how best it can work alongside wider fundraising programmes. But if raising funds from individual givers is a priority for your charity, the signs are that it is an option worth exploring.
Anna Taylor is a freelance fundraiser, writer and researcher and a former UK director of Child in Need India