Does pixel pitch matter?  The image above shows two 8″ tall by 15″ wide modules.  The one on the left is a 4mm pixel pitch while the one on the right is a 6mm pixel pitch.

• The 4mm module (left) has 4608 total pixels (48×96)
• The 6mm module (right) has 2048 total pixels (32×64)

With a 4mm design you get more than double the pixels per module, the result is quality logos and graphics and improved readability at close distances.