How much is Apple getting from Google ?

Apple just announced that Eric Schmidt has been appointed on its board of directors. One question that always puzzled me is how much is Apple getting from Google by bundling a Search box in Safari ?

According to the latest surveys, Safari is about 3% of all browsers. Let's assume that Safari users tend to use Google more than average windows users, and it is not unrealistic to expect that 4 to 5% of all Google searches are done through Safari (and it is growing month after month)... Can anyone tell me what the safari/google deal was like ? Did it have a termination date ? A business model ?

I don't know if it has anything to do with the announcement, but Google should better treat well a customer bringing in maybe $200-300M worth of revenues every year...