Or alternatively...
ITIL is yet more snake oil by those who know little except how to b*llsh*t.
Just take one little part of this, that "if you can't measure it you can't manage it and shouldn't even try". Total rubbish and the cause of most IT screwups. Most of the important factors to do with business success are intangible. They are things like 'innovation', 'customer service', 'efficiency'. By their very nature they are not the type of thing you can put a number on - but people who love ITIL will try. They create 'fake' metrics that stand in for the item under consideration. Maybe they will count patents, or survey the customers, or measure some abstract utilisation figure.
And then it really goes wrong.
People work to these 'fake' metrics. They optimise, they modify, they cheat. Pretty soon the metrics are way up, and the real performance is way down as the fake metrics drives paradoxical behaviours that are against the businesses best interest.
In IT that means measures of effectiveness that totally ignore the staff screaming at a system that doesn't help them deliver their job, and an IT staff that actively gets in the way and prevents change. "But we're following our ITIL approved plan and all our metrics are up."
Save the hundreds of pounds they want for this paperwork jamboree and get a clue instead.