It stands to reason that the most effective IT outsourcing relationships are built on a foundation of commonality. It's one reason why the importance of having compatible values should not be underestimated. For this reason, a willingness on both sides to view the relationship as a 'partnership' and not simply a 'contract' is key.
For us, this culture change programme is not a passing fad, nor is it the pet project of a few people at the top: it has affected every single Grey London employee. I can't speak for everyone, but I know that most never want to work in any other way again, wherever their careers take them. It's that simple and that powerful.