One of the biggest functions of progressive analytics is to optimize voter outreach, and at the heart of that effort is the voter file, a list of every registered voter in the United States along with their name, address, phone number, and previous vote history (whether or not they voted, not whom they voted for). This data is actually publically available, sometimes for free and sometimes for a fee. Sometimes, this data is appended with commercial datasets, which adds records of unregistered voters. Data providers will also add columns to this voter file through other sources, ranging from Census data to datasets of commercial activity. At the end of it, we end with dozens to hundreds of characteristics (often called features) on any given individual. For advocacy organizations, the general voterfile might not be as relevant. Instead they'll focus on their membeship, but even then, that file is often also matched to the voterfile to take advantage of the many features offered there.