For the most parts, charities are going to depend on people in order to survive. You have the Lupus Fund for example, that uses donations from members and from people that want to donate money to the fund in order to allow them to contribute fund for critical research to acquire the causes and curse for lupus. These funds also help support victims that have fallen ill to Lupus as well. These funds and charities don't make money any other way so they absolutely need people TO contribute and TO donate.

For funds such as this one, a Tree Of Life donor plaque would be a terrific idea in order to honor those people that have contributed money towards the fund. Of course people can also be anonymous as well, but a lot of these donor walls and donor plaques are going to be in memoriam of the names of these people that contribute, maybe a name of their company or business (almost like that of a sponsor) and if need be how much they donated.

This is more or less a "thank you" gift to show your supporters how much you appreciate them. You can also purchase individual donor plaques as well - this is nice if you have just a handful of people every year or every month that donate. However, the donor walls are great for charities or funds where you have dozens if not hundreds of people donating.