Alphabet Inc. pays Apple Inc. billions of dollars a year to keep Google as the default search engine on iPhones, according to a note that asset management firm AllianceBernstein L.P. sent to investors last week.

According to Bernstein analyst A.M. Sacconaghi Jr., Google’s payments to Apple could total more than $3 billion this year, which he estimates would account for 5 percent of Apple’s total operating profits for 2017. Sacconaghi also estimated that Google’s payments may be responsible for up to 25 percent of Apple’s total operating profit growth for the last two years, and Bernstein said in its note that it believes these payments account for the bulk of Apple’s services business.

If Bernstein’s prediction is accurate, then Google’s payments to Apple will have tripled in only a few short years, as court documents from 2014 revealed that the company’s payments were just over $1 billion at the time.

Although Apple is clearly benefitting from Google’s payments, Google also stands to gain a lot from the deal, as the company continues to hold a dominant lead in the search engine market, especially on mobile. In its second-quarter earnings report, Google highlighted mobile search as one of its key growth areas, and the company said mobile search played an important role in earning $22.67 billion in advertising revenue for the quarter.

With Google’s strong lead over every other search engine, Sacconaghi said, the company could eventually become confident enough in its position that it might stop paying Apple, hoping that users would choose Google search over a different default search. This would be a risky move, however, as the success of Apple Maps has proven.

Apple Maps had a rocky start back in 2012 with inaccurate directions and other issues, but the app quickly gained speed as it caught up to Google Maps. By 2015, Apple Maps was used three times as often as Google Maps by iOS users, proving just how valuable the position of default app can be.

Photo: Google