From emergency knick-knacks like safety pins to luxuries like champagne and caviar, Phil and Meinir Simpson stock everything their customers could want.
Their Mace store is in the remote village of Dinas Cross, sitting on the Pembrokeshire coastline, just a few miles from affluent Newport and close by to several holiday camps.
During the summer months their turnover trebles, and as the days warm up, so the holiday makers begin to arrive at their second homes in their Lamborghinis, and £50 notes start to appear in the tills of Kiel House Stores.
"The caviar isn't something every shop can do," says Phil, a dairy farmer-turned-retailer .
"But Newport, the next village along is like a little island on its own – it's very wealthy and it's like a ripple effect."
Phil and Meinir Simpson
Kiel House Stores (Mace)
Location: Dinas Cross, Newport, Pembrokeshire
Trading since: August 2002
Hours: Summer: 7am-8pm Mon-Sat, 8.30am-6pm Sun; winter: 7am-7pm Mon-Sat, 8.30am-1.30pm
Size: 1,000sq ft
Style: Convenience store in remote coastal area. Summer trade is three times as great as winter. There’s an elderly population in Dinas, but an affluent one in nearby Newport. Immediate competitor is a Murco/Costcutter service station, with several supermarkets within a five-mile drive.
They sell champagne for up to £35 a bottle and "tiny" pots of caviar for £4 each.
Meinir says: "We had one girl who'd come all the way from Cardigan because she couldn't find caviar anywhere else. She bought six pots."
Since coming under the control of Costcutter group in 2013, Mace's promotions have really taken off – with great deals on brands like Heinz Baked Beans and Coca-Cola.
"It's not just things that are cheap – it's things that people want every day at really good prices," says Phil.
They compete with discounters like Aldi and Lidl by offering a pound zone which includes things like biscuits, chocolates and fruit juices.
A bake-off range (50p white baguettes, 55p brown, cheese and bacon turnovers £1.15) has given them another point of difference. It appeals to everyone from builders to walkers setting off for a trek in the Welsh hills.
1) Offer hot food to go. Getting a bake-off range has been Phil and Meinir's best decision. A cheese & bacon turnover sells for £1.15 with a margin of 30% and also gives people a reason to visit
2) Be different. Kiel House if the only shop within a 30-mile radius that sells caviar (£4 a tiny pot, with a long shelf life). It's an unusual line for a convenience store but it sells well here and is great a point of difference
3) Make shopping easy for your customers. Phil and Meinir arrange with holiday makers to drop essentials like bread, tea, butter and sugar into their campsite homes before they arrive for their break
"We often get the same people coming back – holiday makers who know what we have on offer," says Meinir.
Kiel House also does deals on wine which regularly makes them cheaper than Tesco. Their customers want good wine but won't pay that much for it.
"If people are buying something to eat and a bottle on their way home they don't want to pay £10 for wine – they want to pay £5," says Phil.
"Six quid tops," says Meinir.
One great idea they had was to offer their customers a sale-or-return policy on wine. If there is a party going on they sell a range of wines to a customer and free use of wine glasses, so the shopper can offer their guests a selection. Any wines that are not opened can be returned to the shop for a full refund.
"It's a great way of selling wine," says Meinir.
They stock plenty of local produce which is expensive but popular with their shoppers, and have also made a success with their Barts spices PoS. There is nowhere else nearby where shoppers can buy a star anise, for example. Again, it's not something for every retailer, but here it works a treat.
"The biggest lesson we've learnt is that you've got to change with the times," says Phil.
"When we bought the shop it was a little, very good shop but a little dated. You can maybe get away with having a dated shop if you sell clothes or antiques, but if you sell food you've got to compete. And people want a shop that looks bright and fresh."