Sam Whitelock said he actually preferred to be called Samuel, but would put up with the shortened name.
"People tend to call me Sam and automatically shorten my name," he said.
"Truth be told, I prefer to be called Samuel as that is my proper name. In this case I'm happy to be called Sam if it's getting me a few free rides."
Sam Cane said the common name could sometimes make things difficult.
"There's been a few times where there's been more than one Sam in the room which can make it tricky, he said. "I always think people are talking to me when their actually talking to Whitelock."
He hadn't realised his name was so common, but since joining in the campaign he had met "even more Sams".
Whitelock said he was one of three Sams at his school as a child.
"We were called Sam one, Sam two, and Sam three," he said.
Sams who are keen on free rides must register online by June 30.