How Google Makes $100 Million A Day

There's no doubt that Google is one of the world's most successful companies, and it has been for several years. Their many free services are fueled by revenue acquired from ads of different sorts. Getting an ad based service to work takes a lot of dedication, a lot of work and a whole lot of ingenuity.
It's a process that Google knows very well since we have seen plenty of their services come and go throughout the years. But just how is it that the Google economy is booming so much, and just how does Google rake in $100 million a day?