Campaigns can then merge this information with the other data they have collected on voters over the years to create their database.
Often basic information such as phone numbers and postal codes are not included on the voters list, and the campaign will have to procure this data as well.
These companies often provide United States Voter Files to statutorily permitted or otherwise non-restricted users.
Currently, the Republicans use rVotes Data Center and the Democrats use Votebuilder from the Voter Activation Network (VAN).
There are non-partisan firms that offer registered voter data in the United States, too: NationBuilder, Aristotle, eMerges and Labels and Lists.
Its most recent incarnation is the Labour Contact Creator system, an online tool accessible from anywhere with an internet connection.
Party members and activists are provided with a username and password and voter contact details, preferences, interests, past voting behaviour, and demographic/socio-economic information are available.
The VICS system was the first of its kind to incorporate a geographic street-based reactive demographic model which directed activists towards streets likely to support leaving the European Union.
After major flaws arose in 2013 over C-VOTE (including not being able to identify undecided Voters), the Conservative Party switched back to CIMS for the 2015 election.