They then use various means of communication--direct mail, phone calls, home visits, television, radio, web advertising, email, text messaging, etc--to communicate with voters, crafting messages to build support for fundraising, campaign events, volunteering, and eventually to turn them out to the polls on election day. Microtargeting's tactics rely on transmitting a tailored message to a subgroup of the electorate on the basis of unique information about that subgroup.
Democrats did not utilize microtargeting in 2004. Some news accounts credited Republican superiority in that area for victories in that election cycle. Democrats later developed microtargeting capabilities for the 2006 election cycle. "It's no secret that the other side [Republicans] figured this out a little sooner", said Josh Syrjamaki, director of the Minnesota chapter of America Votes in October 2006. "They've had four to six years' jump on us on this stuff...but we feel like we can start to catch up."
The databases contain specific information about a particular voter (party affiliation, frequency of voting, contributions, volunteerism, etc.) with other activities and habits available from commercial marketing vendors such as Acxiom, Dun & Bradstreet, Experian Americas, and InfoUSA. Such personal information is a "product" sold to interested companies. These data are particularly illuminating when portrayed through a Geographic Information System (GIS), where trends based on location can be mapped alongside dozens or hundreds of other variables. This geographic depiction also makes it ideal for volunteers to visit potential voters (armed with lists in hand, laid out in the shortest route - much like how FedEx and UPS pre-determine delivery routes).
These data are then mined to identify issues important to each voter and whether that voter is more likely to identify with one party or another. Political information is obviously important here, but consumer preferences can play a role as well. For example, Republicans prefer bourbon, while Democrats tend to drink gin. Individual voters are then put into groups on the basis of sophisticated computer modeling. Such groups have names like "Downscale Union Independents", "Tax and Terrorism Moderates," and "Older Suburban Newshounds."
Once a multitude of voting groups is established according to these criteria and their minute political differences, then the tailored messages can be sent via the appropriate means. While political parties and candidates once prepared a single television advertisement for general broadcast nationwide, it is now not at all uncommon to have several dozen variations on the one message, each with a unique and tailored message for that small demographic sliver of the voting public. This is the same for radio advertisement, direct mail, email, as well as stump speeches and fundraising events.