V12 Data - V12 Data offers rich data sets with verified addresses and emails for personalized marketing campaigns.
Lotame - Make your data actionable, learn about your most valuable customers, improve ROI by targeting the right audience and increase relevance across screens.
RingLead - RingLead offers a complete end-to-end suite of products to clean, protect, and enhance company and contact information.
Google Audience Center - 3 votes and 6 comments so far on Reddit
Cloudingo - Cloudingo - a cloud-based SaaS, connects to Salesforce and allows system administrators to scan their entire database for similar or duplicate records.
Clearbit - Clearbit provides Business Intelligence APIs