Clearbit - Clearbit provides Business Intelligence APIs
Google Analytics - Improve your website to increase conversions, improve the user experience, and make more money using Google Analytics. Measure, understand and quantify engagement on your site with customized and in-depth reports.
DataXu - Marketing analytics for brands and agencies.
Optimizely - A/B testing you'll actually use.
V12 Data - V12 Data offers rich data sets with verified addresses and emails for personalized marketing campaigns.
Smartlook - Qualitative analytics for websites and mobile apps Start understanding the 'whys' of your users' behaviors with clear, visual insights. With session recordings and event tracking, you get the complete picture.