Our market development (telemarketing) team uses Marketo programs to automate their process and those programs are dependent on tracking sales email sends, opens and clicks, so they are totally on-board with this. The sales team also values the availability of Sales Insight templates about new features, case studies, events etc., and the visibility they gain into sends,opens and clicks. In addition, they use the Log with Marketo function to keep a central record of the sales emails they receive from their prospects. Plus whenever a recipient clicks a link in a sales email, it helps ensure that they have a cookie, so the sales team can be alerted to website visits. The only group that we haven't had full and enthusiastic usage of the add-in is our customer success team. The difference is really due to the buy-in of their respective management teams, but I continue to evangelize to the customer success team and am slowly making progress.