The mobile brand's Head of Internal Communications, Paul Diggins, shared the success of the incentive developed by Grass Roots, with delegates at the Event UK conference in Birmingham this morning.

The agency was given the task of raising enthusiasm and knowledge across the workforce in advance of launching T-Mobile's latest £30 price plan.

Diggins said: "It had a phenomenal impact on our contract business. Within a month, our presence in the £30 price sector, which was what we were targeting, grew from 10% to 40%. And our overall market share was up 5% year-on-year in a declining market."

He was speaking at a seminar on the power of experiential events and was joined on stage by Grass Roots' recently-retired Head of business Development, Graham Burt.

The incentive scheme was rolled out in all of T-Mobile's UK stores & call-centres and included product knowledge quizzes, prize draws & an on-site recreation of T-Mobile's TV ads.

"It was a way of getting the messages across in a fun and a memorable way," said Burt. "We engaged and involved staff. They had fun but they also learned."