i don't know why no one answers. maybe because everyone knows it or no one does...however i found out:
" In their early years, Coldplay was also widely noted in the media for their claim to give 10% of their band's profits to charity. Bassist Guy Berryman says, "You can make people aware of issues. It isn't very much effort for us at all, but if it can help people, then we want to do it". "
this is much better than many other artists, although they could do more...but i do not want to... well you know. it is great what coldplay is doing. maybe they will spend more in the future, when they know that they have enough money for their rest life.