(CNBC) — Amazon could rival the nation’s big banks in as few as five years, capitalizing off its digital prowess and massive consumer base, according to a Bain & Company report.

“We could imagine Amazon’s banking services growing to more than 70 million U.S. consumer relationships over the next five years or so — the same as Wells Fargo, the third-largest bank in the US.,” wrote Bain’s Gerard du Toit and Aaron Cheris. “Although many retail bankers and observers have pegged the nimble fintech start-ups as the likely disrupters, it has become clear that established technology firms pose a bigger threat.”

Pushing customers toward a co-branded banking account also allows Amazon to cut down on transaction costs, Bain said.

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