BTL marketing stands for "Below the Line" marketing, which is a more targeted and direct approach to marketing. It involves promoting products or services through mediums other than radio, television, billboards, print, and film. BTL marketing activities include promotional events, direct mail advertising, trade shows, presentations, and in-store marketing. BTL marketing is aimed specifically at targeted individuals that have been identified as potential customers. It is best for conversions and direct response, and is designed to ensure direct consumers for the product or brand by focusing directly on return on investment (ROI) and gaining user conversions.

BTL marketing is different from ATL marketing, which stands for "Above the Line" marketing. ATL marketing has a very broad reach and is largely untargeted, and is mostly used for building brand awareness and goodwill. TTL marketing, on the other hand, stands for "Through the Line" marketing, which is an integrated approach that uses both BTL and ATL marketing methods to reach the customer base and generate conversions.

In summary, BTL marketing is a highly targeted and direct approach to marketing that involves promoting products or services through mediums other than traditional mainstream options. It is best for conversions and direct response, and is designed to ensure direct consumers for the product or brand by focusing directly on ROI and gaining user conversions.