In three years, Lebanese grocer Ali Khiami hired six staff, invested in property and funded his children's university education. Business is booming -- thanks to Syrian refugees using UN debit cards.
Displaced Syrian families in Lebanon are using electronic cards, topped up each month by the UN's World Food Programme with $27 per person, for their grocery shopping.
The WFP scheme has both helped refugees and delivered a windfall to cash-strapped Lebanese shop owners.
"This programme changed my life. I bought an apartment in Beirut and I paid for my three children's college degrees," said Khiami.
Since registering with the WFP, he has seen his personal income skyrocket from $2,000 per month to $10,000, allowing him to pay off a long-standing debt.
"I used to sell goods worth about 50 million Lebanese pounds (around $33,000) per year. Today, my turnover reaches 300 million pounds," said Khiami.
A small blue sticker in the window of his cosy store in southern Beirut identifies it as one of the 500 shops taking part in the WFP scheme.
Lebanon, a country of just four million people, hosts more than one million refugees who fled the conflict that has ravaged neighbouring Syria since 2011.
The influx has put added strain on Lebanon's already frail water, electricity and school networks.
The World Bank says the Syrian crisis has pushed an estimated 200,000 Lebanese into poverty, adding to the nation's one million poor.
With 700,000 Syrian refugees benefitting from the programme, the debit cards are offsetting at least some of that economic pressure.
When they buy from Lebanese shops, the country's "economy is also benefitting from WFP's programme, not just Syrian refugees", WFP spokesman Edward Johnson told AFP.
The UN agency says Syrian refugees have spent $900 million at partner shops in Lebanon since the programme was launched in 2013.
It selects stores based on their proximity to gatherings of Syrian refugees in camps or cities, as well as cleanliness, prices and availability of goods.
Umm Imad, a Syrian customer at Khiami's store, said shopping with the card makes her feel much more "independent" than with the WFP's previous food stamp programme.
"Now I can buy what I need at home," she said.
The scheme has also changed perceptions.
Instead of seeing refugees as a burden, shopkeepers like Khiami see them as potential customers to be won over.
He has begun stocking items favoured by his Syrian customers, such as clarified butter, halawa -- sweets made of sesame, almonds, and honey -- and plenty of tea, "which Syrians love".
"Syrian customers have bigger families, so they buy more than Lebanese customers," he said.
'We sell more'
Ali Sadek Hamzeh, 26, owns several WFP-partnered shops near Baalbek in Lebanon's Bekaa Valley, where dozens of informal refugee camps have sprung up on farmland.
"In eight months, I rented three new locations to stock merchandise and opened up a new fruit and vegetable store," Hamzeh told AFP.
He said Syrian refugees make up around 60% of his customers, but he has also attracted new Lebanese clients with his lower prices.
But for some shop owners, partnering with the WFP has had a downside.
Omar al-Sheikh manages a shop in Nuwayri, a district of western Beirut.
Since he registered his store with WFP in 2013, his monthly profits have nearly doubled from $5,000 to $8,000 -- but at a price.
"My profits went up, but I have lost about 20% of my Lebanese customer base. Lebanese customers do not like it when it is busy," he said.
But Sheikh said he would continue to serve his Syrian customers.
"These are human beings. Their country is at war and we should help them."