Jon Gertner has written a useful article on combining voter databases with other profiles:
So who are they? Where are they? Are they rich, with three kids and a jumbo mortgage? Do they own fly rods and drive minivans? Do they go to church or temple? And maybe most important, who among them has never voted, or rarely voted, or voted in ways that may deserve the special status of swing voter? To do the job right, of course, to really win this thing, you’ve got to find them, woo them and get them to the polls. Where to start?
These days, the first stop is a comprehensive database of U.S. voters. There are fewer than half a dozen of them. One, named Voter Vault, belongs to the Republican National Committee; another, named Datamart, belongs to the Democratic National Committee. Over the past few years, thanks to technological advances and an escalating arms race between the parties, Republicans and Democrats have gone to great lengths to make campaigning more like commercial marketing. Moreover, both parties have begun to sort through their troves of information in order to identify and then court individual voters.
The result: direct mail and phone calls during the election season…

Fascinating look at national fund raising data.
While it is no secret that New York and Los Angeles are money meccas for both Republicans and Democrats, what about Teton County, Wyo.? Or Greene County, Ga.? Or Blaine County, Idaho?
Candidates reached into all quarters of the country to raise money last year, including some places that are not part of the well-worn money trail that presidential candidates walk every four years. In many cases, candidates found money in unusual places thanks to fund-raisers who happen to live and work there. Glen Justice, New York Times.