Craigslist started in 1995 as a local San Francisco newsletter and has grown to host classified ads for over 450 cities worldwide. It allows users to browse classified ads online or post their own ads for free in categories like jobs, housing, items for sale, and services. Craigslist has a simple signup process that requires only a valid email address to create an account. Users help monitor site content by flagging interesting or inappropriate posts. The article will examine Craigslist's impact, corporate structure, and some controversies surrounding the site.