Related Clues:

• Stops up
• Promotes
• Advertises
• Tune-up needs
• Name-drops a product
• Electrical connectors
• Power points?
• Toupee alternative
• Fills, as gaps
• Stoppers
• Socket inserts
• Power connectors, or a way to describe 17-, 22-, 55- and 61-Across
• Sink stoppers
• Promotions
• Sneaky ads