Related Clues:

• "Besides which ..."
• "Let's not forget . . ."
• "As if that weren't enough..."
• The first 'A' of 51-Across
• ''Plus . . .''
• It's beneficial
• "Besides which . . ."
• ''More than that . . .''
• Starter with "ran"
• Start of an addition
• "Wait, there's more"
• Favorable factor
• An advantage; positive
• A bonus
• An advantage