The ease of creating multiple campaigns for different segments within one account is great! It's also very intuitive once you get used it (which takes less than 5 minutes). I wish there was an option where we could send out emails without having them go into spam folder in some clients' inboxes - but that may be because my client doesn't have enough subscribers yet so they aren't getting much volume either way from this feature right now anyway :) We're trying everything possible at all times just like everyone else when using MailChimp or any other provider these days ;).