Making a phalanx with fellow slow drivers

If people want to drive below the speed limit, that’s fine — really. However, do you think anyone’s ever noticed when there’s no traffic in front of them, then looked in the rear-view mirror (not) and noticed that there’s a mile’s worth of cars behind them, because they’re going 10 mph under the  posted speed limit, next to someone who’s going 10.1 mph under the posted speed limit, next to someone who’s going 10.2 mph under the posted speed limit? (License plates reading New York, British Columbia, and Minnesota, respectively.) If you want to make friends, don’t be ignorant or inconsiderate.