Search engine

I want to do a custom search engine and 75% of its income to donate. Do you think someone would use my search engine?

OMG you just gave me an idea!!!

Yes, I think they would. There a few companies already doing this. Please see the article below for more info on those companies.
http://www.doshdosh.com/13-charity-search-engines-that-help-you-give-money-to-charity-for-free/

I can't imagine why charities aren't promoting this more aggressively. Its the easiest way for them to make money.