It's important to "really" know your audience. Many people tasked with communicating to a wide audience assume readers have sufficient "real world" experience and college-level reading ability (In the language being used) in which to be able to "really" understand the message that is trying to be conveyed.
There was a time people actually had a love of words, think back to the time of Shakespeare. Now it seems people take a certain pride in trying to communicate with others with the fewest characters (not words) they can. This is causing people to have shorter and shorter attention spans.
"Executive Summaries" are a great way of providing a simplified explanation of a topic and cater to those folks with short attention spans.
If you choose to use abbreviations or words not commonly used it is helpful to provide an explanation of their meaning.
Lastly, writers often focus their attentions on details (or choosing just the right words) and completely forget to call the readers to some kind of action. Some folks have more time than money, while others have money but little free time. Most any call to action can readily utilize both so don't focus all of your attention on one group. Give your readers a multitude of ways to be of service in the short and long term.