What are some alternatives?
Outreach - Outreach Is Your Sales Communication Platform
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
SalesLoft - The simpliest way to build the most accurate and targeted lists of leads on the internet
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.
Yesware - Sell smarter with email tracking and more
LinkedIn Sales Navigator - Sales tool for LinkedIn users.