Clearbit - Clearbit provides Business Intelligence APIs
V12 Data - V12 Data offers rich data sets with verified addresses and emails for personalized marketing campaigns.
DataXu - Marketing analytics for brands and agencies.
Lotame - Make your data actionable, learn about your most valuable customers, improve ROI by targeting the right audience and increase relevance across screens.
Google Audience Center - 3 votes and 6 comments so far on Reddit
Amobee DSP - Cross-Channel Advertising