This is the second in a series of articles derived from “Meeting the Growth Challenge Requires Precision Over Volume,” a white paper produced by Curinos on why the old playbook for retail banking is failing, what the data actually shows, and how the banks winning in 2026 are making decisions differently.
Where does a bank’s deposit growth actually come from? In any given year, three-quarters of it, on average, comes from customers the bank already has. Not new-to-bank acquisitions. Not through promotional campaigns. From the accounts already on the books. But most of the budgets, dashboards, and energy point the other way – to acquisition, which is only 25% of the growth.
Annual Deposit Growth Contribution by Source
Note(s): New-to-Bank (NTB) customers are defined as those with tenure under one year; back-book (existing) customers have tenure of one year or more | Balance acquisition includes deposits from new customer acquisition, account openings by existing customers, and balance increases | Scope is limited to the Retail LOB and Deposit Products only (Checking, MMDA/Savings, CDs) | Source(s): Consumer Deposit Analyzer | Curinos Analysis
Not to say acquisition isn’t critical. This year’s new customers are next year’s existing ones, and a book that isn’t replenished eventually evaporates. Acquisition and retention are complementary, not competing, but the problem is one of proportion. Most institutions over-index on chasing the next customer and underinvest in growing the ones they have. That’s in part because new customers are visible and CPA is easy, while the quiet compounding of existing relationships is hard to see and rarely measured.
There’s also a limit to how far the remaining 25% can be improved. Just 6% of people switch providers each year, and only 15% of them bring more than $10,000. That means that roughly 1% of prospects represent meaningful value. And winning them on rate backfires: only 25% of promotion balances are new money; the other 75% is cannibalized from the bank’s own lower-rate accounts. Rate also selects the most price-sensitive customers, the first to leave at the next offer. Win on rate, lose on rate.
This isn’t an argument for more loyalty programs. It’s about value that compounds invisibly through customers that consolidate balances and deepen over years without responding to a single campaign. An FI’s best opportunity is a customer it already has.
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