I like that it can be used to scan many different devices with ease without having to do any configuration or installation of software! This really helps when you are trying to find out what all your endpoints have been doing at one time but cannot remember if they were up as long ago as 2 years prior since we had so much activity happening during those times for our business line.
Not sure how well this works over mobile apps however (which would make sense). We use these services quite often now because its easy to see exactly where there has been some sort of suspicious behavior going back months/years before someone even knew about something being wrong.