V12 Data - V12 Data offers rich data sets with verified addresses and emails for personalized marketing campaigns.
Clearbit - Clearbit provides Business Intelligence APIs
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.
Datalogix - Oracle announced that it has signed an agreement to acquire Datalogix to extend Oracle Data Cloud with industry-leading solutions for data-driven marketing to inform and measure cross-channel digital marketing.
DataXu - Marketing analytics for brands and agencies.