Assmosis is the process by which people absorb success and promotion by sucking up to the boss and not rocking the boat, rather than by thinking the unthinkable and working hard. And if it isn't, then it should be.
In the traditional marketing world, I've observed it from afar in the way some executives climb the greasy pole by dint of managing ever-larger product accounts. They get a new role on the basis of having demonstrated the ability to run the previous one; immediately demonstrate their dynamism by organising an advertising review and instigating a new beauty contest for agencies; and their ruthlessness by removing the contract from the incumbent. They then go through the machinations of preparing and launching a new campaign and, before any results are in, move on to another role with bigger budgets on the basis of having managed the previous one.
It's marketing viewed as an organisational function (rather than the key driver of all businesses) and a reflection of the domination of boardroms by finance departments. But in our changing world of advertising-aversion and quicker turnaround in marketing initiatives and their more easily-observed results, it is to be hoped that this pattern will change.