[feature] GUI to see how many leads are in which stages of a campaign

[RCheesley]

Personally I find the decisions and actions tabs on a campaign super confusing, I don't really understand what it was supposed to demonstrate but I can't get my head around it, let alone explain to clients!

I think it would perhaps be more beneficial to have those displayed as a graph/chart - maybe a funnel? This could perhaps show the number of leads at each point in the process, which can be exploded to see the individual leads.

An example might be:

Email 1 sent ----- > Opened by (5) Not opened by (15)
Visit to landing page 1 ---- > Visited by (10) Not visited by (10)

What would be super cool is if you could also make some smart list from these screens - say if I wanted to do an out-of-campaign mailer to everybody who hasn't opened, or even add a new action to the campaign etc.