The best feature I like is that you can have multiple employees working in different locations but share their data with others who are not physically present at work.
Some people might find this difficult to understand so it's good if there was an option to explain how your system works as well (for example, what happens when someone shares his/her account). It has been very helpful during my internship period while doing online research or using various applications simultaneously without any interruptions from other users sharing same accounts. Also helps make sure all sales records get entered into one central database which makes record keeping much easier than maintaining several copies individually.