The best feature is that they have all products in one place so it saves time, I also like to shop at Amazon from there but sometimes i don't find exactly what im looking for or when things go wrong then its really frustrating which makes me not want use this software anymore! They should include more features of other platforms eg facebook etc as well because some people would be interested with these additional services too!! There are plenty reviews online about how easy their service was compared to others (ie amazon) just do your research before you sign up make sure everything works perfect firstly.
And if possible try using them out yourself maybe even talk/chat live via video call through skype/google hangouts ect.. Its worth giving them another chance by trying it myself :).