The star of Twitter's U.K. holiday ad this year is John Lewis. That's the American academic John Lewis, who receives thousands of tweets--particularly around this time of year--destined for the British department store. 

Lewis, a computer science lecturer who resides in Blacksburg, Virginia, has the Twitter handle @johnlewis and is regularly mistaken for John Lewis, the retail store (Twitter handle @jlandpartners) known for its award-winning Christmas commercials. (Admittedly, we are among the guilty.) 

His Twitter bio includes the words "not the retail store." But his Twitter fame equally derives from his witty and well-timed responses to the tweets. When people inadvertently tag him, he replies directing them to the store, and he comes up with his own hilarious tweets too: for example, on the morning the real John Lewis ad came out, he wrote "I deliberately slept in a bit this morning. Big mistake." 

In the Twitter film he's seen at his desk in Blacksburg, Virginia (3,683 miles from the U.K., we're told), replying to tweets in his own inimitable style while a guitar player sings a doctored version of "In the Bleak Midwinter." Look closely at the set and you'll see other cheeky references to the John Lewis ads of years gone by, such as toy penguins ("Monty's Christmas"), a telescope ("Man in the Moon") and an alarm clock ("The Bear and the Hare.")

The spot concludes with the words: "This Christmas. Join the conversation. Even if it's by mistake."

The campaign was created by PR agency The Romans, which is part of Mother London. "The perennial story of @johnlewis patiently replying to tweets is one that has delighted the U.K. for years and truly captures the spirit of Christmas," says Joe Mackay-Sinclair, founder and creative director. "We're very pleased to have been able to finally let John be the star of his own campaign."