I like that we have access to our data at any time from anywhere in the world with no limits or restrictions! There are still some features missing but this will come as more people use it so there's hope! The biggest challenge has been getting users of all different levels onboarded into using their tool effectively - once you get your first user though even if its just one person who knows how to do things properly then everything else comes easy after that.
It helps us track customer activity across channels (e-mail, web chat etc) which allows me to proactively reach out when certain customers need attention before something goes wrong i.e. an abandoned cart issue.