The ease of use! I have been using this for several years now with no problems at all - it's very user friendly! It is great that they are constantly updating their product line so there isn't any issues when we need something new or changed down the road. They also offer excellent customer service if needed as well. Nothing really comes up from time-to-time but having someone available who can help us out right away would be nice sometimes too!! We don't run into many things where our system doesn't do what we want it to anymore either though. This has helped me keep track of everything related to membership records within my organization without needing multiple systems/tools.