If you were wondering why Apple would bother releasing Safari for Windows, the answer is actually pretty simple: money. Sure, it contributes to the “iPod halo effect,” and it gets WebKit out there as a more prominent rendering engine, but the big reason is probably just cash. Every time you use the built-in Google search bar in a web browser, Google gives a small cut of the proceeds to the maker of the browser. That small cut adds up. According to Daring Fireball:

Safari is a free download, but it’s already one of Apple’s most profitable software products. […] Apple is currently generating about $2 million per month from Safari’s Google integration. That’s $25 million per year. If Safari for Windows is even moderately successful, it’s easy to see how that might grow to $100 million per year or more.

There’ve been many attempts to finance app development with advertising; what’s interesting about web browser search engine deals is that browser developers earn money – a lot of it – for ads that users were going to see anyway, just by performing the same search without the built-in integration.

One wonders what would happen if Google stopped being the dependable cash cow all these business models depend on it being.