Adobe Audience Manager - Adobe Audience Manager is a data management platform that integrates online and offline data to deliver a unified view of all your audiences
V12 Data - V12 Data offers rich data sets with verified addresses and emails for personalized marketing campaigns.
Google Audience Center - 3 votes and 6 comments so far on Reddit
Openprise - Openprise is a data automation solution that automates the analysis, cleansing, enrichment, and unification of your data.
Clearbit - Clearbit provides Business Intelligence APIs
The Trade Desk - The Trade Desk is an online demand-side platform that provides buying tools for digital media buyers.