I think it all started with email. It became easy, fast and cheap to send a message. So the inevitable happened - information and the number of messages people are sent exploded (note that I did not say the number they received).
As a marketer, your job is to make your message, regardless of the medium, be one of the many that actually gets through.
I have noticed an interesting screening mechanism that people use - the length of the message. If the message is short they read it. If it is long, they do not.
Look at business books. The length has dropped to about 200-250 pages in order to be saleable. People no longer think they get more value if a book is a 1000 page tome.
Instant messaging is a hot phenomenon, especially with younger people who have grown up in the age of uber technology and information overload.
And Twitter's rampant success with a maximum of 140 characters is remarkable. We can all learn from Twitter; it can teach us to keep it short. I advocate that every marketer should sign up for Twitter and try sending 20-30 Tweets. It is good training on how to get a message across in less words.
Cut the message length and increase the impact. Less is more.