What makes a message effective?

After reading President Bush's address, I realized I needed the audio to make the  message more  personalized to me .  I couldn't read through the whole thing. It was eloquently, written. So therefore, I decided to read it while listening to the audio clip. It was impressive how my point of view took a switch  after that simple added dynamic.  My point of view of Bush is closely related to his sound which is ironic because I'm a visual learning. Perhaps, the many times I have seen Bush  on the screen added to some type of of affirmation I get when I hear his voice. If needed I'll elaborate later.
After using the added device of communication, I myself felt a little compelled to take upon an attitude that we are doing what was best for the country as a whole during the war in Iraq. I give credit to the writer of the speech , not the deliver of the message. The world usage gave the speech an element of Identification and also a weird sense of ownership, that ironically is the motivator of invasion instead of assistance. This is  only from my perspective. (disclaimer)
After seeing the almost questionable wikipedia stats , I saw a different dynamic of what politicians would say is the voice of the people.  The variation of the stats within the last three post was interesting. Could there been a  correlation of relevance within the addition of the posts?  I most admit that I was a little alarmed when I encountered the link provided was a wikipedia page. I have been taught to take the information provided with a grain of salt when it comes to its inputs from visitors. Therefore while reading, I already had a biased attitude attached to my intake of " biased" information. However , the medium is driven by the people so I am receiving  at least  a glimpse of what the people think, right?
I feel duration has something to do this media effect. The inputs on wikipedia shows how the people became less "pro"-war during the long  extension of time.Perhaps, the longer a message exist during time , it may affect its relevance, and therefore the results of causing a direct action towards a message with this effect would make the message less powerful. Does this mean in order to be effective in  causing  a change in an  attitude through a message,  relevance would need to remain fervent and influential ?