[darkerside]

People aren't machines. We don't take an input and process it completely the first time. Human functions are not idempotent because we are stateful to the extreme, and when we hear the same message, we process it a different way the second time.

Repetition is a tool. Repeating yourself is useful. When I was younger, I thought it was good to be brief, succinct, and concise (and for some purposes, it is). But with most audiences, repeating yourself several times, as I have done here, is your best chance at getting your message to actually hit home. People need to understand and process your idea from different angles and perspectives, and if you aren't able or willing to take efforts to make yourself understood, they will justifiably not make the effort to understand you either.

Or, as I could have said more succinctly, there is value in repeating an important message in different but overlapping ways.

[taphangum]

Very well put. To add to this, the onus is really on the writer to help the reader understand. Repetition is one of the best tools for this.

If your reader doesn't get it, they blame you. So its wise to use all of the tools at your disposal.