Clearbit - Clearbit provides Business Intelligence APIs
InsightSquared - #1 for Salesforce.com Pipeline forecasting, profitability analysis, activity tracking: all the small business intelligence you need. Works using CRM data and automatic syncing.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
Aviso - Aviso provides predictive analytics software to help sales organizations optimize their performance and exceed revenue goals using machine learning algorithms and portfolio management techniques.
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.
Sidekick by Hubspot - Customer insight integrated with your email tools.