Proximity marketing is a strategy that uses wireless technology like Bluetooth, NFC, and SMS to deliver targeted advertising or information to customers based on their physical location near a business. It works by constantly broadcasting marketing content via Bluetooth or embedding NFC tags with offers, which customers can access if they have a compatible mobile device. Proximity marketing allows businesses to connect with potential customers they wouldn't otherwise reach and provides advantages like free and measurable campaigns, location-based targeting, and helping customers access relevant offers.