Inspired by suggestions from Hemant Mehta.
Ten percent. Ten percent BEFORE taxes. Now, that's tithing. Mormons, Catholics, Jews, Muslims, and Protestants, they all have a rich tradition of giving money to the community, or to the religious institution that they belong to. The religious will give on a regular basis, and step it up a notch for special projects, such as a new building, or aid relief. Having been raised in a religious tradition, I can tell you that not everyone who attends a church will contribute financially to the organization, but will donate time. There are still those who will do neither. The last statistics I remember hearing about the church I last attended, was that half of the membership gave every week, a quarter gave about once a month, and a quarter gave nothing. Still with these statistics, the church was able to build large facilities with class rooms, meeting centers, and worship areas, as well as paying a large number of full time staff. The weekly attendance was around 2,000, which is far greater then any atheist organization I have ever seen, but I have seen churches with membership around 300 who have a building to worship in, pay a pastor and usually a secretary, and still participate in community events.
Are the faithful better at giving money? I think the example provided proves that at least the religious are more focused in their giving. I've known many generous atheists since I've been active in the community. Some feel the need to support atheist organizations, and others spread their money to organizations who actively help the poor by providing shelter and food. There are still others who give most of their money to animal shelters, research organizations for the cure of diseases, and places that help battered women. By the time the local or national atheist organization comes around, they are already worn thin. This is a minority of people, however.
Why don't people feel the need to give money to atheist organizations? Part of the reason, I have seen, is that atheist groups don't do much other than provide a social community. As long as someone brings the cookies, you don't need to raise any money, right? Atheist organizations can be much more than just a group of friends who get together. There are a lot of atheists out there who feel that they are alone. There are atheists who see separation of church and state concerns, but feel like there is nothing they can do. Still others want to help the community by volunteering or donating to a cause, but don't want to sit through another patronizing prayer before getting to work.
When I think about supporting an atheist organization, I want to see them doing something. Even if it is as simple as publishing their position on issues, or writing letters of concern to schools which may be treating the non religious differently. I want to feel like the money I give is going to be used for something helpful. That is why I support atheist organizations who do charitable work. It may be a small part of what the organization does, but I feel that the money I have given has gone to a good cause.
Why don't atheists contribute more to atheist organizations? Part of the blame is on atheist organizations themselves. The local atheist andfreethought groups in the Twin Cities have been shy about asking for money. Minnesota Atheists went over a year without sending out a fund raising letter. When we speak to the general public, we rarely speak about membership and how people can support us. Part of it, I think, is because of the personality types atheist organizations seem to draw. Members are more introverted, and don't want to feel too pushy.
The other reason atheist organizations have trouble raising funds, is that atheists generally see themselves as being independent. I've heard a number of times while working in the public for Minnesota Atheists, "Since when does having a lack of belief in God cost money?" Then, I have to try to explain that renting table space at an event costs money, printing fliers and sending in speakers all cost money, but they still don't get it, and don't find value in supporting an organization which is actively engaged in making the community more welcoming for atheists.
Atheist organizations need to make it as easy and as automatic to contribute as possible. Public media has been very successful at promoting small monthly donations, and offering token gifts to contributors. While more and more organizations do have regular monthly giving options, it needs to spread more. More incentive, even it it's something small, like a book, would help inspire more people to give regularly. Ask a student, for example, to donate $60 to the local atheist student group, and they'd laugh at you. But, say, "Hey, would you miss $5 a month?" After a year, the donation is the same. Most people, no matter how down on their luck, or small their income stream, $5 a month is doable.
As long as atheist organizations make it clear what your money is used for, are not shy about asking for funds to keep them operating, and make it as easy as possible to automatically donate, atheist groups will be able to do more than they thought possible.