The web page you pointed out is another example of a broker buying business. What he's doing so publically is done by many agents all over the country. I know so many agents who give percentages of their income to local charities. Brokerages also have programs that give back, for example Coldwell Banker nationally gives to Habitat for Humanity. We do it on the local level by having build days and we also hold fundraisers. There is a large number of agents in San Francisco that support EARN, a non-profit that teaches financial management and mathches savings $2 for $1. In fact our association supports it too.
This giving isn't used to drum up business, it isn't touted as the reason to chose one over the other. Our giving is done from a generous heart not to buy business.