Optimizely - A/B testing you'll actually use.
ShareThis - Grow your audience with easy-to-use sharing tools.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
Shareaholic - Shareaholic is trusted by over 300000 brands, businesses, agencies, and individuals to grow website traffic and engagement 24 hours a day, 7 days a week.
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.
Sharingbuttons.io - Quickly generate social sharing buttons with a tiny performance footprint.