New data shows those special prices at the supermarket offered only to loyalty members often aren't that special after all.
Consumer NZ tracked 25 items offered at what the supermarkets claimed were exclusive deals - only to find that it was usually just an average market price, or even more expensive.
A Consumer NZ survey shows 84 percent of Kiwis are signed up to one of the big two - New World's Clubcard, and Woolworths' or Countdown's Everyday Rewards.
"They're trying to drive you to be loyal, to shop at a particular place to get these member deals, but we think what they're offering is not a particularly great or competitive bargain," said Gemma Rasmussen of Consumer NZ.
Consumer NZ used its Price Pulse technology to track 25 grocery items at Countdown and New World, not including fruit and veg, offered on special yesterday exclusively to loyalty members.
At New World, the member-only price was a good deal only 16 percent of the time - mostly, it was just the average market price over the last 40 days, or even more expensive.
At Countdown it's a bit better right now, as the new Everyday Rewards launches, but the exclusive member price is still a only good deal 56 percent of the time. The rest of the time it was the average market price or dearer.
The items selected were on special yesterday, but to loyalty members only. The Price Pulse tracker was able to look back at the price of the identical item across major retailers over the last 40 days, and take an average price from that. The items do not include loose fresh produce.
Countdown told Newshub its pricing is commercially sensitive, but that Everyday Rewards offers a multi-million-dollar increase in rewards compared to its predecessor Onecard.
New World owner Foodstuffs said its card offers savings, giveaways and options to earn Flybuys, Airpoints or New World Dollars.
But if we don't sign up, we can be hit with much higher prices.
For example at Countdown, loyalty customers pay $3.30 for Leggo's roasted garlic pasta sauce, but if you're not signed up, it's $5.30 - 40 percent more. You can get the same thing for $3.29 at PAK'nSAVE today.
Purina One kitten food 1.4kg is $18.80 for loyalty customers, but non-members will pay $29.99. It's almost exactly the same deal with New World's Clubcard. But the product is available for $20 at The Warehouse.
"There can be a lot of pressure to sign up to a loyalty card just to get prices that are accessible," said Rasmusen.
The advocacy group has also noticed more and more so-called specials at Woolworths are only being offered to members.
"It looks like what Woolworths is looking to do is roll out these exclusive member pricing deals, and that's what we are starting to see more of."
The Grocery Commissioner Pierre van Heerden said: "I would like to see more widespread use of Everyday Low Pricing (EDLP) rather than the practice of frequently moving prices up and down - to help ensure Kiwi consumers are getting a genuinely good price when they shop for their groceries."
Signing up for loyalty cards also means handing over your data.
Woolworths and Foodstuffs say personal data collected for the cards, like your name and address, won't be sold or passed on to other companies.
But encrypted, anonymised and aggregated data harvested from the cards is shared with third parties such as Facebook and Google who use it to better target their ads.
Consumer NZ advises checking prices at other retailers to make sure that member-only deal is actually saving you money.
The Grocer app allows you to load in your local supermarkets and compare prices in real time.
More from the supermarkets:
Newshub asked the supermarkets how often their loyalty card member-only pricing is cheaper than the average price for that item over the prior six months. They declined to directly answer.
A Countdown spokesperson told us: "Our pricing and promotions are commercially sensitive. However, we think we offer our customers fantastic value. The new Everyday Rewards programme delivers a multi-million-dollar increase in rewards from its predecessor, Onecard. Every week, our team works hard to create specials that provide the best value for money for customers."
New World's owner Foodstuffs said: "With lots of active users in New Zealand, New World's Clubcard delivers heaps of rewards and offers a multitude of benefits, from savings on groceries, opportunities to enter exciting competitions, access to exclusive giveaways and options to earn Flybuys, Airpoints Dollars, or New World Dollars that can be redeemed at New World for groceries. "
The rewards:
You also collect points, but the discount is very low. With Woolworths, you get $15 to spend in-store for every $2000 you spend.
And with New World, it's $5 to spend in-store when you spend $700. Or you can choose to earn Flybuys or Airpoints instead.
Data collected through supermarket loyalty cards:
New World has clarified how it uses the personal information collected via its Clubcard.
Owner Foodstuffs told us: "We use non-identifiable and aggregated data gathered through the Clubcard programme to better understand our customers, so our teams are able to ensure we consistently meet their needs by stocking the right range of products."
"All New World Clubcard information which could be used to identify a customer, such as their name or email address, is held by Foodstuffs and not shared with the likes of Google or Meta. This data is always anonymised and aggregated to respect the privacy and security of our customers.
"When we receive customer service queries, we do sometimes share customer information with our loyalty partners at Air New Zealand and Flybuys when it is needed to resolve the issue. Queries are assessed on a case-by-case basis and always in line with our obligations under the Privacy Act."
On passing on information to Google and Facebook, Countdown told us: "We might engage these types of service providers when we advertise e.g. on Google ads or Facebook, but only want to advertise to a certain group of customers. We create these groups of customers in our system and encrypted information is passed to our service providers to see if the customer matches their database and should be served (or not served) the advertisement. After this process is complete, the service provider immediately deletes the information we provided. This is industry best practice for placing targeted advertisements, and the same process is used by other retailers throughout New Zealand and the rest of the world."
