While the number can't be confirmed, Google might be paying $3 billion a year to Apple to be Safari browser's default search engine.

Although most of the time the two tech giants seem to be big competitors, in case of the default search engine choice, the companies seem to be working together. According to reports, Google was paying $1 billion a year to Apple to be the default search engine for Safari back in 2014, but now the number has potentially increased, based on Bernstein report.

One billion is a pretty big number already, three billions obviously way higher. But why has the number gone up? If you'd ask Bernstein analyst Toni Sacconaghi, he'd most likely tell you that since 2014 the sales of Apple devices have gone up and now Apple is the world's top smartphone vendor with roughly 18% market share.

Also, based on documents, Apple is making more money from licensing now and Google traffic acquisition costs have grown as well.

Putting all that together, the $3 billion estimation might be spot on.