Even smug people like me who pay their bills in full each month to rack up cashback still largely pay for their own rewards because, as behavioural economists point out, humans spend more on plastic than they do when forced to spend cash.
The most common perks are cash back and vouchers.
Other rewards include:
Air points
Air New Zealand credit cards and OneSmart allow you to build up points to spend on free flights, upgrades or lounge access.
The other option is to use a regular cash back card such as ASB True Rewards or Westpac's hotpoints and redeem your points on a House of Travel voucher for example.
Travel insurance
If you travel a lot, "free" international travel insurance on your gold or platinum card can be very worthwhile.
I've written previously about why I always travel with my gold card insurance.
Buyer beware, however.
This article here: http://tinyurl.com/goldcardinsurance explains some of the risks such as the need to activate the insurance for it to be used.
What's more, the rental car insurance cover in "free" travel insurance isn't always adequate as I wrote last week.
Purchase protection and extended warranty insurance
Some of the Gem credit cards offer a variety of insurances as perks such as breakage cover for six months on items you buy with the card.
It will also refund the difference if you find a product cheaper within six months of purchase and will pay off your balance if you lose your job and don't get another one within 90 days or if you can't work due to illness or disability.
Westpac cards and others offer purchase protection and extended warranty cover.
Concierge desk
Platinum is the new gold and if you're wealthy enough to qualify for a platinum credit card you'll usually get access to a 24/7 concierge desk that can help you book almost anything you need from a tradesman to concert tickets.
Balance transfers
If you pay interest on your credit card then none of the perks above add up financially.
Zero or low interest balance transfer cards are a better perk for someone in this situation.
But be very wary of spending on the new card whilst you're paying it down, says Jose George, general manager New Zealand at Canstar.
New spending is charged at a higher rate, which catches a lot of people out.
Whether or not credit card perks make financial sense consumers have really embraced them, says George.
"But it's only giving them extra value if they have the correct credit card for their spending habits in the first place.
"Don't simply be romanced by the incentives."
Do the maths and ask yourself:
• What's my monthly/annual spend?
• How and when do I pay my balance?
• What is the annual fee for my card?
• How does the rewards scheme work and what can I earn?
The equation can get complex. Some cards have different rates of rewards for different spends or they have additional insurances.
And if you get paid in vouchers, a-la Fly Buys, calculate what the item you buy would have cost you on sale at a retailer, not the RRP listed on the Fly Buys website.
Canstar released its latest comparison survey this week and rates the Warehouse Money Purple Visa card best for rewards seekers who pay their bills on time and spend around $12,000 annually on their card.
For those in the annual spend categories of $24,000 and $60,000, BNZ's Advantage Visa Platinum Fly Buys rated highest in both.
But before you trade in your low rate card for a reward card, remember that too many of us fall into another behavioural economics trap.
That's believing that "found money" such as a credit card rewards is somehow different to other money.
I only spend my rewards and Fly Buys points on essentials that I would buy otherwise.
Beware, however, of not spending the money at all.
Expired points are even more worthless than ones used to buy an unnecessary gadget.
