For years we've been advised to shop around for financial products. Whether it's a loan or savings account, we are told not to stay put with our current provider as it is more interested in snaring new customers.
But in recent months the high street banks seem to have changed their attitude.
"Other businesses have known for a long time that it costs more to acquire a new client than to keep an existing one," says Dennis Hall, founder of Yellowtail Financial Planning. "Maybe now the froth has gone out of the market, the banks have realised this."
So how well are the banks prepared to reward loyalty?
"At First Direct we value our current account customers," explains Rebecca Hirst, spokesperson for the bank. She says this is why its mortgages are only available to people with a First Direct current account.
Given First Direct is regularly at the top of the best buy tables for mortgages - and was a winner in Moneywise's 2012 Mortgage Awards - being a customer could save you a great deal when it comes to buying a property.
First Direct isn't the only bank to offer special mortgage deals to its customers. Santander, Nationwide and NatWest also offer preferential rates to people who hold another product, usually a current account, with them.
For example, Nationwide only offers its four-year fixed-rate mortgage to FlexAccount customers. Santander current account holders get a one percentage point discount on its mortgage rates - so if the rate on offer to the wider public is 4.19%, a Santander customer with a current account or existing mortgage would get the same mortgage for 3.19%.
As for NatWest, if you are an Advantage Gold customer you may get a preferential rate on your mortgage.
Loans and credit cards
It's not just large products such as mortgages where banks are offering preferential rates, many banks also offer great deals on personal loans.
Nationwide offers existing FlexAccount customers its lowest loan rate of 6.3% APR for borrowings of between £7,500 and £10,000 for up to five years. HSBC offers its customers 10% cashback on its loans, working out at a rate of 6.2% APR. But the best rates on the market are 6%, so this is one area where loyalty may not pay.
As anyone who's ever tried to borrow money knows, lenders like to know as much as possible about the person they’re lending to.
If you have an account with a bank, it already knows about your finances and how well you handle your money. This makes you a less risky proposition, hence it may offer you a better rate.
The same is true of credit cards. Some banks offer preferential credit card rates to their own customers as you are seen as a safer bet than a complete stranger. For example, only Nationwide FlexAccount customers can apply for the Select Credit Card, with rates from as low as 9.9%.
But when it comes to credit cards, as with personal loans, there are better deals available on the wider market. For example, Sainsbury's Bank has a low-rate credit card that has an APR of just 6.9%.
However, Santander 123 current account holders can get the bank's 123 cashback credit card fee-free (the standard fees are £24 a year) for the first year if they apply before July. Given the card offers competitive cashback rates and plans to expand the offer, it's worth snapping up.
Also, if you have a spotted credit history, you may find your own bank will give you a better rate than a credit card company that has no financial link to you.
But it's not just borrowers who can use their relationship with their bank to their advantage.
Preferential rates for savers
Many banks offer preferential rates to their savers, too, and some of these really are market leaders.
For example, if you are just starting out saving and looking to build up a pot, you may want to consider becoming a First Direct customer. It offers current account customers a regular savings account that pays 8% interest. The next best account on the market comes from Nottingham Building Society, paying just 5.99%.
If you already have a savings pot and are looking for a new home for it, it is worth asking your bank if it can offer you a special interest rate.
Nationwide recently got more than it bargained for when it offered all its FlexAccount customers an instant-access Flexclusive ISA, paying 4.25%.
The rate was miles better than anything else on the market and led to a deluge of applications. As a result, the rate was subsequently cut to 3.5% and the account was pulled from the market a month later. By that point, Nationwide had received more than 100,000 applications.
Santander also offers preferential savings rates to customers on occasion. In the past, it has offered a Loyalty Flexible ISA paying 3.5% and a Loyalty Fixed Rate Monthly Saver with a 5% interest rate. Neither of these products are on offer at present but "may be re-opened in the future", says Jonathan Akerman, a spokesperson for Santander.
So if you are looking to open a savings account, check what your bank can offer you as well as shopping around on the wider market.
Finally, there is another area where remaining loyal to your bank can save you money - insurance.
A lot of the high street banks offer insurance deals to their customers. These can range from free mobile phone or travel insurance to home contents cover.
For example, Nationwide FlexAccount customers get free travel insurance and a 10% reduction and three months' free cover with their buildings and contents insurance. The Co-operative Bank also offers insurance deals to customers, with Privilege current account holders getting a 20% reduction on their first year's Co-op home insurance premium.
All in all, there are some good deals out there for existing customers that you should consider when you are shopping for financial products.
Also, keep an eye out at certain times of the year, during ISA season, for example, when some particularly amazing deals, such as Nationwide's Flexclusive ISA, can appear.
But don't be blinkered, you should always check the rest of the market - loyalty may pay but blind loyalty will cost you.