V12 Data - V12 Data offers rich data sets with verified addresses and emails for personalized marketing campaigns.
Uniqode - Uniqode: Revolutionizing QR Codes, Simplifying Solutions.
Lotame - Make your data actionable, learn about your most valuable customers, improve ROI by targeting the right audience and increase relevance across screens.
Radius Networks - Radius Networks offers mobile proximity technologies.
Google Audience Center - 3 votes and 6 comments so far on Reddit
AltBeacon - AltBeacon is an open and interoperable specification for proximity beacons.