The average video on YouTube is watched for less than 15 seconds, then people switch.
www.12Seconds.tv has taken this concept further in that 12 seconds is the maximum length of the video you can post on the site.
On twitter the maximum length of message you can post is 140 characters. Twitter has 4-5 million users. People are becoming conditioned to short fun size messages.
It’s getting harder to ask people to read your long stuff.
The message is get to point quickly or else I will go else where.