Definitely do not agree with Robert Mercer. If a meeting is important enough for him to attend, someone can deputise for him “back at the ranch” while he is at it. If it isn’t important enough, he need not attend. There is nothing worse than trying to make progress in a meeting (whether you are running it or attending it as a participant) than what RM says : “if you see one of your attendees thumbing their blackberry, then apparently your content is not terribly important, relevant, or interesting. You want me to stay off my email, then improve your meeting.” If attendees are doing this, then they are not concentrating and no progress will be made. If the meeting is not good enough, then instead of checking email, the participant can say “I think we are getting off track here/taking too long/can we move on” etc. Mentally switching off and doing something else while half-listening is not only rude it is a huge waste of collective time.