LONDON -- Each year, the run-up to Christmas is bursting with twinkly lights, festive music and Christmas adverts. And, every year, there's always one advert that guarantees to reduce you to uncontrollable tears.。

This year, the most powerful advert didn't come from big brands, like the UK retailer John Lewis or the clothing giant H&M.。

The tear jerker of the season came from an erstwhile unknown auction website in Poland called Allegro. The advert hit 7 million YouTube views in 10 days. At the time of publishing this story, the view count was over 8 million and climbing.。

The reason for its success isn't just down to its endearing plot line about a lonely elderly chap who learns English. The real reason is because it tells an all-too familiar and globally relatable story about the reality of immigration. 。

The advert follows the elderly man's endeavours to learn English, and we gradually see his determination and proficiency increase. But, only at the very end of the ad do we discover the truly moving reason for the man's dedication in mastering the English language. It's because his son lives in the UK, and his grandchild's first language is English.。

The fruits of his labours pay off in the very final moments of the advert when he meets his grandchild for the first time and introduces himself in English as tears roll down his cheeks.。

But, the gentleman's situation is far from unique in Poland. In fact, according to Allegro's brand manager Michal Bonarowski, the man's experience is one that's almost universal for most Polish families.。

Thanks for signing up!。 "Everyone in Poland has or knows someone who is in such a situation, so in some way it is a true story," Bonarowski told。Mashable。

A teary-eyed grandfather introduces himself in English to his grandchild.Credit: allegro。

'Something true to life' 。

Recent figures show that 3.3 percent of live births in the UK were born to Polish mothers -- a figure that's 12.5 times higher than it was in 2004, when Poland joined the European Union. And Poland is the most common country of birth for mothers born outside the UK.。 Bartłomiej Nowak -- managing director of BARDZO, the creative agency behind the ad -- told
。Bartłomiej Nowak -- managing director of BARDZO, the creative agency behind the ad -- told 。

Mashable 。

that the agency wanted it to be based on something true to life.  。

"When thinking of creative concepts, we always look for true insights," Nowak said. "Recently, many Poles have left the country -- almost a million -- and emigrated to Great Britain to look for jobs. We have just shown a real situation in our film," he continued.。

As of 2015, an estimated 831,000 Polish-born people were living in the UK, which makes Polish people the largest foreign-born group in the country. And, the number of Polish-born UK residents has increased by 750,000 since 2004.。

'People can find themselves in it'。

Bonarowski -- Allegro's brand manager -- believes the advert's emotional quality is due to the fact that the story appeals to people from all over the world who have witnessed their own family members moving to foreign countries.。