From free Christmas bottles of wine to bigger IKEA breakfasts, here are Conor Pope's tips on making the most of the glorified data trackers...
It's a natural instinct to politely – but very firmly – decline when a cashier asks you if you fancy signing up to their store's club scheme, but there are rare cases where your back pocket would benefit from getting onboard.
With the vast majority of offerings amounting to miserly savings after months of effort – essentially serving as a front for harvesting customer data – it's hard to know which cards are worthy of taking up space in your wallet.
That's where Conor Pope, consumer affairs correspondent for The Irish Times came in, critically cherrypicking the most worthwhile deals around for The Pat Kenny Show.
So what are the best bets, according to Pope?
Boots Advantage Card
"A large number of people got in touch to say the Boots Advantage Card was the one that they thought was the best. I have to say for full disclosure, I have one of these as well. It is very attractive, because it's a money back scheme...
"So with this card, you get four points for every euro spent. Now typically, a loyalty card will only give you back one point for every euro spent and one point typically is worth a cent.
"[With this] you're getting four cents back... for every euro spent. When you spend €50, you earn 200 points, which is converted into €2 worth of vouchers.
"What Boots have done is they have targeted certain groups carefully. So if you're over 60 and you buy Boots own-brand products, you'll get 10 points for every euro spent. That's a 10% return on your purchases.
"Similarly, if you're a parent of a child under three and you're buying baby products, you get 10 points back for every euro spent.
"They might [tell you to] buy whatever particular range of products they want to promote and you get extra points.
If you use that card wisely, you can actually save a few bob."
O'Briens Wines Loyalty Club
"Probably at the other end of spectrum... Again, you get a point for every euro spent on spirits and beer, and three points for every euro you spend on wine.
"Personally that appeals to me because I would rarely buy beer or spirits. I can't remember the last time I bought spirits in an off-licence – but I do buy wine.
"If you were to buy four bottles of wine a week, you'd earn yourself 6,240 points over the course of a year, and that's enough to cover three fairly expensive bottles of wine for your Christmas table. So that's the kind of return you're looking at."
Arnotts Wonder Card
"The points allocation is similar to the [Brown Thomas] scheme – for every €1 spent you get a point, and then you get the birthday treat triple points [available on the seven days surrounding your birth date] as well. The points do expire but only after 18 months and they're on a rolling basis...
"The thing that really bugs me about [BT's] particular loyalty scheme is that on May 31st every year, all the points earned for the previous calendar year expire."
IKEA Family Card
"I'm a big fan of IKEA; it's the kind of place you could get lost in. You could almost go there on a family day out.
"The card is very handy. You won't get points but you will get free tea or coffee on midweek mornings – not Saturdays or Sundays.
"You also get your sixth item of breakfast for €2.50 if you have the IKEA card with you, which is ridiculously cheap when you think about it. You will get discounts on certain products and they will flag those products instore."
Cream of the supermarket crop
"They're all much of a muchness.
"With the Dunnes [VALUEclub card], you get one point for every €1 spent. Spend at least €200 and you start getting vouchers in the post in April, August and December. They do tend to run points promotions and you can get extra points if you buy a particular range.
"The Tesco Club Card, very similar to the Dunnes one. One point for every €1 spent. Again, it runs certain schemes throughout the year, where you can earn triple points.
"A unique selling point: it's a boosting system. So if you have 250 worth of vouchers, that can be worth a tenner in Milano or TGI Friday, or it can be worth a tenner for days out with your family."
A lot of coffee companies will just have a little cardboard card. There's 10 coffee cups on the card, when you get to the 10th one, you get a free cup of coffee. They're a great scheme. Every two weeks you'll get a free cup of coffee. And people are creatures of habit; they don't tend to go out of their way for a cup of coffee. They'll go to the place that's on their way to work or whatever it might be.
"If you look at the different chains, Butlers and Insomnia give you every 10th coffee free.
"The Butlers people shade it, I think, because they give you a free chocolate with the coffee and that's always to be welcomed!
"If you actually look at the numbers, with both Insomnia and Butlers, you get €3 back for every €27 spent.
"With Costa Coffee, you get five points for every €1 spent. A point is worth a cent, so you need 300 points to get a coffee – you'd have to spend €60 to get to a free coffee. In terms of value, it's half as good as the other ones. But they're grand if they're on your route and it'd be foolish not to sign up to them."