The next time you perform a search on your iPhone and find the result on Google, know that Google paid an obscene amount of money for the right to be the default search engine.

Google and Apple have had a cordial working relationship for years that is underscored by a bitter rivalry. However, money is there to be made and Apple is raking in the profits by taking advantage of Google’s intent on keeping its search engine as the default choice on Safari for iPhone users. According to analyst Rod Hall, Google is paying upwards of $9 billion for the right.

Nothing is more important for Google than for users to be using its search engine, from where its sprawling advertisement empire gains a lot of its data, and one of the most important avenues is smartphone search. The most popular smartphone in the world is the iPhone, and as such, Google is forced to pay a premium to its rival to keep its search as the default choice.

As Hall put it, “Apple is one of the biggest channels of traffic acquisitions for Google,” and Google can’t afford to put a dent in this traffic. Thus, as the price of keeping Google the default search engine in Safari goes up, Google continues to fork over the money. Now it’s reached the jaw-dropping sum of $9 billion. Rod Hall revealed the number is only going to climb higher, with it possibly reaching $12 billion in 2019.

It may sound weird for bitter tech rivals to work together, but it actually happens quite a lot. Samsung supplies Apple with OLED panels for the iPhone and Apple uses Google and Amazon’s cloud servers for its iCloud service. It’s just part of doing business and when billions of dollars are being exchanged, it makes it a little easier to set aside conflicts.