I can see that some causes attract more support than others and I have been guilty of that myself. When I first started clicking on these sites I did only click on certain ones but now I just do the whole lot; as you say it takes no time at all.

I also try to fill most of the charity bags that are posted through my letter box. However, I don't fill the ones that I think may be involved in animal experiments. If I give to an animal charity I do try to give the same to a charity for children. To try to answer your question, I think that we do what makes us feel good and that is an individual thing. I also think that charities that appear to relieve suffering are more popular than those where the suffering is less obvious. Also, helplessness is popular - if you can understand what I mean.

get in there and DO SOMETHING yourself

It isn't always possible for people to do something themselves and if they make the odd donation or click the odd site then it will always be welcome. I have to say that I have stood in the centre of Harrogate collecting for HADA (Harrogate Alcohol and Drug Agency), I have collected door to door for Christian Aid and I have baked cakes and done sponsored walks etc. I'm at the point where I feel that donating is all that I am willing (and sometimes able) to do but for those people who do DO SOMETHING there is a great deal of satisfaction - it is worth it.