I've read a theory somewhere (too lazy to find the source, sorry), that people tend to care more about a cause that they have already donated to. Possible expla

I've read a theory somewhere (too lazy to find the source, sorry), that people tend to care more about a cause that they have already donated to. Possible explanation is trying to avoid wasting money: "if I already spent money on this, it better be successful, or else my money will be wasted". If it is true, there is a value in getting people to donate something, however small, because it makes them more likely to donate or help in other ways in the future.