Asia is the best place to be a banker during the financial crisis. The region is home to a population that holds 60 to 80 percent of its wealth in bank deposits. Bankers across the region can expect more deposits as bear markets continue to scare off investors.

Bank deposits in China rose 18 percent from 40.2 trillion yuan in January 2008 to 47.4 trillion yuan in November 2008 as global financial turmoil took a toll on equities (seen in the Shanghai Composite's record 65 percent drop in 2008).

Some banks in China have seen spectacular deposit growth as investors seek safety. Deposits at China Merchants Bank, the country's sixth-largest lender, grew 42 percent last year, the highest joint-stock bank growth rate. Reasons for the dramatic increase include a strong deposit franchise, a focused retail banking strategy and interbank deposits attracting through brokers. China Construction Bank recorded a 21 percent increase in the same period.

The deposit surge might seem like a sudden abundance of riches for banks but the trouble is it won't be evenly distributed and it won't be cheap for banks competing for these deposits. A fierce battle among banks in China and throughout Asia is shaping up to win these swelling deposits and still make adequate returns.

Banks eager to take advantage of this opportunity need to establish new ways to win customer loyalty. The region's bankers are currently overly reliant on wealth-management products and consumer and corporate lending to fuel revenue and earnings growth. But the weakening economy has many customers bailing out of investment products, credit cards and loans. The best option for reinvigorating banks' business lies in Asia's unglamorous but deep pools of retail deposits.

The banks that attract the most new depositors can expect to increase their deposit revenues by 20 percent to 35 percent in 12 months. China's banks, with their extensive branch networks, enjoy a big edge over many multinational rivals but their passive approach to collecting deposits from customers already inclined to save puts them behind the ball.

Customers used to seeing high returns during the market upswing will be unwilling to settle for the low yields currently paid on conventional accounts. Intensifying competition for deposits risks driving down returns as banks, unaccustomed to playing offense, may succumb easily to pressure and tactics from more sophisticated financial operators.

Customers will move their assets to banks that offer the best combination of value, convenience and returns. Banks should be willing to pay some kind of premium to attract new customers and retain them.

Johnson Chng, Sameer Chishty and Nick Palmer are Bain partners.