Listen very carefully, I shall say this only twice…
‘To get employees to do something, managers need to ask them at least twice.’ – Harvard Business Review.
Managers are combining different types of communication, such as email, IM and phone calls, to repeat and reinforce key messages, and so:
‘Managers who were deliberately redundant [i.e. used multiple channels of communication] moved their projects forward faster and more smoothly.’
Politicians have known this for a long time which is why they pick a few key messages and repeat them ad nauseam. Marketing folk too.
Why is this necessary? Because people have to deal with a lot more information and many more channels of communication than ever before.
Some people can cope with this and have good tactics for filtering, prioritising and acting on messages (zero inbox, anyone?) but most people are prone to ignore or defer messages, especially if they require work. If you don’t ask twice, they think, it’s probably not important to you. And thus the squeaky door gets the oil.