Is it possible to view in Sales Insight the number of times that a lead has opened an email? When sending an email through Salesforce, reps can view how many times, and the last time, a lead has opened all of the emails that he/she has received, and we cannot do that currently with SI.
I am not aware of a counter that you can put in place, but you can create an interesting moment every time they open an email. That would get quite cumbersome, so you can create an interesting moment if they open a certain email 2, 3, 4... times. And you can put the number in the description of the interesting moment so your rep knows the count. Not ideal, I'm aware, but it's one workaround.
You might also create Score type fields for opens and clicks of the latest email. When a new email was sent, it would reset those fields. You can view the Sales Insight Score tab to see the click and open dates.