Long tail marketing refers to targeting niche markets and less popular products or services that collectively make up the majority of sales. While the head of the market consists of a few popular products that make up 20% of sales, the long tail is made up of many less popular products that collectively account for 80% of sales. Implementing a long tail marketing strategy involves targeting niche audiences and keywords through organic search, paid search on platforms like Google Ads, and social media engagement. This allows businesses to profitably reach customers throughout the tail through lower production, distribution, and marketing costs compared to competing for mass market audiences.