Much research has demonstrated that people are bombarded with multiple forms of media. Further, the vast majority of people who use on-line resources use a search engine, like Google. Despite giving them a direct URL to a favored disaster prep info site, people will just search for info on a topic. Think about it, when was the last time you used a bookmark or typed in a direct URL into your web browser?
People find all sorts of information, some accurate, some not. Some giving folklore (like standing a doorway in case of earthquake) or sharing info about "what we've always said," such as "be prepared for 72 hours." (The 72-hour reference has been traced back to a 1949 publication about nuclear attack preparedness; it has *nothing* to do with disaster preparedness self-sufficiency and gives an unintended false impression that the cavalry will arrive at hour-73.)
The foundation of the National Disaster Education Coalition's work from 1992 to 2004 was to gather all Federal Government and national not-for-profit organizations who shared a stake in communicating with the public about disaster preparedness, and to review all of "our" messaging. Was it accurate? Was it based on science? Did it reflect social science research? Was it understandable, free, available, and in the public domain?
When messages are standardized by consensus agreement and then used by all communicators on all platforms, the messages are consistent no matter where people find them in search results.
Thus, more people are likely to do what you want them to do. Message: Be consistent!