Lotame - Make your data actionable, learn about your most valuable customers, improve ROI by targeting the right audience and increase relevance across screens.
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.
The Trade Desk - The Trade Desk is an online demand-side platform that provides buying tools for digital media buyers.
Clearbit - Clearbit provides Business Intelligence APIs