Shoppers lined up outside Aldi stores to buy Logan Paul and KSI's coveted Prime drink. The retailer used a clever strategy to lure customers in.

• Aldi confirmed it had sold out of Prime just one day after the drink hit its shelves.
• People waited outside stores before they opened in their scramble to buy the coveted drinks.

Huge lines formed outside Aldi stores across the UK on December 29, the day that the German discount retailer put a drink called Prime Hydration on its shelves.

The bottles look unassuming. Large text on the side states the drink's name, and the plastic is in block bright colors.

But the drink is the brainchild of YouTubers Logan Paul and KSI, and its release has drummed up a huge amount of hype, leading to a huge online resale market. The drink has been so hard to source that people have been paying to download the Prime Tracker app.

Asda was the first UK retailer to start selling Prime, with the company limiting it to three bottles per person. But the drink's release at Asda didn't garner quite as much of a social-media buzz as Aldi's release did. Experts say Aldi used a clever strategy to lure in shoppers by create a feeling of exclusivity and notion of scarcity.

Aldi released Prime in the UK as a so-called Specialbuy, known as Aldi Finds in the US, charging £1.99 ($2.40) per drink and limiting customers to three bottles – one in each of the flavors it stocked. Aldi quickly ran out of the product, and some stores appeared to sell out within minutes of opening.

Aldi's rollout of Prime was a "huge success," said Richard Lim, CEO of consultancy firm Retail Economics.

Though Aldi is best known for its groceries, twice per week the retailer rolls out a new range of products, which can vary from garden furniture and kitchen appliances to fitness equipment and food.

Aldi secures a set quantity of its Specialbuys which it sells using the mantra "once they're gone, they're gone," and Prime was no different.

"It was the right strategy," Dr Ceyda Paydas Turan, senior lecturer in marketing at Kingston Business School, told Insider. She said that selling a limited stock of Prime created a sense of urgency, putting pressure on shoppers to buy it while supplies lasted.

To some onlookers, Aldi's rollout of Prime looked like chaos. Bloomberg reported that more than 100 people were waiting outside a store in southwest London the day the drink was released. But Paydas Turan said that even the videos circulating on social media showing huge lines of people simply made shoppers want the drink more because it seemed rare and exciting.

Paydas Turan said that of all demographics, younger consumers in particular prefer limited products because they make them "feel special" and create a sense of community. "The ownership of something that's so rarefied and highly desired is particularly appealing for young people," Lisa Conway, a senior lecturer in business and management at Chester Business School, told Insider.

The YouTubers have been turning to their huge social media following to promote the drink. Logan Paul has 24.6 million Instagram followers and 23.6 million YouTube subscribers, while for KSI those numbers are 12.4 million and 16.1 million respectively. The duo also partnered with British football club Arsenal to sell the drinks at its matches.

The @drinkprime Instagram account now has 1.3 million followers.

Paydas Turan said that it was "very tough" to operate in the beverages market which has prominent brands such as Coca Cola, PepsiCo, and Nestlé, but that the YouTubers were a "perfect match" to promote Prime, with many of their followers likely being interested in such a drink.

Aldi sold the drink at £1.99 a bottle, and Prime sold 12-packs for £24.99 ($29.60) on its UK website before they sold out. Despite the huge demand for the product and resellers successfully listing drinks for £8 ($9.50) a bottle on eBay, Conway said that Aldi likely stuck to a low price because it didn't want to go against its reputation as a cost leader.

It's unclear how Aldi beat other retailers to get its hands on Prime or how much stock it was able to source.

Prime isn't the first time Aldi has hit the headlines for its Specialbuys. Sarah Montano, senior lecturer in marketing at Birmingham Business School, told Insider that Aldi tried to mirror key trends with its time-limited offers, pointing to its sales of air fryers and home-heating devices as households try to cut down on gas and electricity consumption amid the energy crisis. Aldi is "very very good" at positioning products as specials, Lim said.

Montano said that grocery shopping was "fairly habitual," with customers largely returning to the same stores, based mainly on proximity. But offering Specialbuys could help persuade shoppers to choose Aldi over other stores, she said.

Conway said that Aldi was likely strategic with the timing, waiting for the Christmas rush to be over. Aldi likely had other priorities during the holidays and didn't want "the added complication of this arriving," she said.