Ever since he was a little boy, James King has been faithful to his bank.

He set up his first bank account, with his father, at a Canada Trust branch in Sault Ste. Marie, Ont., where he grew up. Now 32, and a web developer living in Ottawa, Mr. King still relies on the same institutional piggy bank to safeguard his money.

Better still for Toronto-Dominion Bank, which swallowed Canada Trust whole, his financial life is much more involved than it was 25 years ago: He has a mortgage, a credit card, a retirement savings fund, some insurance, a home equity loan. As with many Canadians, his banking relationship runs deep.

Story continues below advertisement

"Part of the motivation for putting everything in one spot is convenience," Mr. King explained. "I log into online banking and everything's there."

For lenders, this level of loyalty is largely good news. But it's also a problem. Banks have now so thoroughly saturated the Canadian market that a good chunk of their growth has to come from poaching each other's customers. As online services, such as automatic bill payments, and increasingly complex banking products tie people to their lender of choice, it requires more and more ingenuity to sway potential clients.

"Switching rates [of customers between banks] have come down drastically," said Anatol von Hahn, Bank of Nova Scotia's head of Canadian banking.

Five years ago, about 15 per cent of Canadians were prepared to switch banks, according to Scotiabank. New data show that figure is now in the mid single digits, and Mr. von Hahn expects it to slide further.

Despite grumbling about issues such as banking fees, most customers resemble Mr. King – they like their banks, or are at least satisfied enough with them to stay.

"As a general rule, Canadians are happy with the service they are getting from their financial institutions – there's a comfort zone," Mr. von Hahn said. "Something pretty harsh has to happen to you, with your existing relationship, to make you want to say, 'Okay, I'll switch.'"

Banks have a lot riding on keeping their customers loyal. Personal and commercial banking is enormously profitable, generating $16-billion in earnings across the Big Six banks in 2013. Given the scale, growing market share by only 1 or 2 per cent is considered a major victory.

Story continues below advertisement

The fight to lure new customers has the banks trying novel strategies. One tactic is to target people through indirect channels. If Bank of Nova Scotia can't lure a personal banking account from TD, for example, Scotiabank hopes it can at least sign up customers of its rival with its Scene loyalty-reward partnership with Cineplex Entertainment. By getting a foot in that door, Scotiabank aims to eventually cross-sell products such as mortgages or insurance. Its database of potential customers is huge, with Scene already boasting a membership of five million Canadians.

Royal Bank of Canada adopted a similar strategy with plans to cross-sell products to the customers it inherited in the recent acquisition of Ally Canada, a financial institution that specialized in auto loans. "All roads can lead to a primary banking relationship," said Mike Dobbins, RBC's executive vice-president of personal financing products.

Banks are also focusing with laser-like precision on the shrinking number of Canadians who are willing to switch. This involves attracting potential customers at key financial moments in their lives: as they head to university, buy their first home, have their first child, or start saving for retirement. On Bay Street, such windows are referred to as "moments of truth."

Targeting newcomers to Canada is crucial as well. RBC recently made it easier for immigrants to obtain credit, while Canadian Imperial Bank of Commerce signed a deal with exclusive rights to set up branches in Toronto Pearson International Airport, so it can try to sign up newcomers the moment they arrive.

Thankfully, the retail client war comes with one respite, said Ernie Johannson, Bank of Montreal's senior vice president for personal banking. After a splitting of the Aeroplan rewards card portfolio between CIBC and TD, there has been a rare shake-up in the usually static credit card market, putting millions of clients up for grabs. Sensing an opportunity to win back old customers and add new ones, the banks are spending tens of millions each to advertise their own cards.

For the most part, however, it is a tough slog to win retail customers because even high banking fees aren't always a deterrent. Mr. King acknowledged he probably pays too much for his accounts with TD, but he rationalizes the expense: "What's a few bucks a month? I feel I get better service."