In the best case, Consumer said a good card would give someone "enough rewards points to enjoy a small treat." But in a worst-case scenario, high annual fees would leave the credit card owner with virtually nothing.
"When we last looked at these schemes in 2011, the returns they offered were disappointing. Not much has changed," Consumer reported.
The study said even when a person spent $25,000 over two years, none of the cards tested would pay for a $600 return flight from Auckland to Sydney.
"When we deducted the cost of annual fees to get the net value, eight cards resulted in a negative return," Consumer added.
Consumer said people had to "spend big" to earn decent rewards.
"Don't spend just to earn a few extra points: the returns aren't worth it. These schemes only make sense if you earn points as part of your regular purchases. If you're selecting a rewards card, make sure you take the annual fees into account. High fees can quickly erode the value of the points earned."
The study said high card fees meant earning points to buy goods could be less than rewarding.
"Eight of the 19 cards that offered shopping voucher rewards had a negative net value," Consumer reported.
Rewards depended in many cases on card fees, and how and where cards were used.
"Unless you're a big spender, the returns are likely to be limited. And if you don't pay off your credit card balance each month, interest charges on the unpaid balance will quickly outweigh the value of any rewards."
Consumer analysed specific cards and spending scenarios.
A BNZ Visa holder would have to spend $9250 to earn enough Fly Buys points to buy a $40 toaster. To get a $70 dustbuster, worth 320 points, a person would need to spend $16,000 on this card, Consumer said.
The same dustbuster needed spending of $11,850 with an ASB True Rewards Visa. And on Westpac's Hotpoints MasterCard, a customer would have to spend $9400 before claiming the dustbuster reward.
Gold and platinum cards offered a higher rate of return on spending, but also had higher annual fees, Consumer said.
The organisation was now offering a rewards calculator on the Consumer website to compare net rewards earned with different cards.
"ASB, BNZ and Westpac allow you to convert your reward points into KiwiSaver contributions but only for KiwiSaver accounts held at the bank," Consumer reported. "If your KiwiSaver is with another provider, you won't get this option."
Consumer said credit card companies were often big beneficiaries of the reward schemes.
"As well as encouraging loyalty, reward schemes give companies access to a wealth of data about their customers' shopping habits, tastes and lifestyle."
An ANZ spokesman said it was up to customers to choose which card is best for them, how much they spend on the card and when they repay their credit card balance.
"ANZ card reward schemes consistently offer some of the best Airpoints rewards of any card in New Zealand.
"This is reflected in our ANZ Airpoints Visa Platinum card being the most popular Airpoints earning credit card in New Zealand."
Glen Martin, head of cards at ASB, said the bank had different cards for different customers.
"We recognise that all customers are different and it is important our customers understand the options available and that they get the right card for their needs," he said.
"For example, if a customer does not intend to clear their balance each month, an ASB Low Rate Card is likely to be the best option for them.That's also the best option for a customer who wants a credit card for emergency use only.
A comment was expected from BNZ later.
REWARDS OFFERED
For spending of $25,000 over 2 years:
Best flight rewards:
American Express Air New Zealand Credit Card $250
Diners Club Golf Credit Card with Double Points $178
Diners Club Golf Credit Card $149
ANZ Qantas Visa $142
ANZ Qantas Visa Platinum $117
Worst flight rewards:
American Express Air New Zealand Platinum $-457
Westpac Hotpoints World MasterCard $-405
Westpac Airpoints World MasterCard $-395
BNZ Visa Platinum $-155
ASB Visa Platinum $-50
Best shopping rewards:
Diners Club Golf Credit Card with Double Points $161
Diners Club Golf Credit Card$140
Farmers Finance Card$140
BNZ American Express Classic$127
The Warehouse MasterCard$111
Worst shopping rewards:
Westpac Hotpoints World MasterCard -$363
ANZ Qantas Visa Platinum -$121
BNZ Visa Platinum-$117
Diners Club Personal Credit Card-$56
ASB Visa Platinum-$50
For spending of $10,000 over 2 years:
Best flight rewards:
American Express Air New Zealand $100
Diners Club Golf Credit Card$60
BNZ HomeAdvantage MasterCard$31
ANZ Qantas Visa$17
Kiwibank Air New Zealand Airpoints Low Fee MasterCard$1
Worst flight rewards:
American Express Air New Zealand Platinum -$657
Westpac Hotpoints World MasterCard -$630
Westpac Airpoints World MasterCard -$626
BNZ Visa Platinum -$272
ASB Visa Platinum -$200
Best shopping rewards:
Diners Club Golf Credit Card$56
BNZ HomeAdvantage MasterCard$37
Farmers Finance Card$20
BNZ American Express Classic $15
The Warehouse MasterCard $3
Worst shopping rewards:
Westpac Hotpoints World MasterCard -$613
BNZ Visa Platinum-$257
ANZ Qantas Visa Platinum -$229
ASB Visa Platinum-$200
American Express Platinum Edge Credit Card -$195
Source: Consumer NZ
