A direct mail campaign is a marketing effort that involves creating and distributing promotional materials through physical mail to generate sales, leads, or brand awareness. Direct mail campaigns can take many forms, including postcards, flyers, catalogs, or letters, and are targeted to a specific audience based on demographic, geographic, or psychographic information. A direct mail campaign typically includes a call to action, such as a special offer, coupon, or request for further information, and may be executed in conjunction with other marketing channels, such as email, social media, or online advertising. The success of a direct mail campaign can be measured through metrics such as response rate, conversion rate, and return on investment and can be optimized over time through data analysis and testing.