While automatic voter registration is gaining ground, we're still missing millions of eligible people on the voter rolls - 6,868,736 of them in California alone. It's not easy to increase voter registration, but for the nonprofits and elections agencies looking to get more folks registered, there are a number of data-driven and tech-enhanced organizing strategies that reduce the burden.
First you need a good data set on the unreachable voters. I'd start with an official state list of registered voters or a list from NationBuilder - then I'd compare it with phone append vendor Accurate Append's list of adult consumers. Accurate Append can provide phone numbers and opt-in email addresses for millions of eligible but unregistered voters as less cost than a traditional political data vendor.
Once I've got the unregistered adults with contact info, things get really fun. Here are three ways to reach and register these folks:
Custom audiences: With phones and emails, you can load a list of these folks into Facebook for laser-targeted advertising campaigns.
Texting: Services like HandStack mean you can reach targeted segments easily by texts, which have a much higher open rate than emails.
Peer-to-peer: With volunteer teams, Amicus' postcard tool and VoterCircle's peer organizing via email and text come into play. There's no better way to reach and convince folks to become voters than with messages from their own friends.