I like that it is so easy for our customers, as they can call in with their phone number or email address from anywhere! It has been great having this service available during COVID-19 pandemic because we have not had any issues since switching over two months ago!! Nothing at all really - just be sure you are using good quality internet connection when calling through an app vs traditional landline phones (we use Skype). We were able get away without spending much money up front but there's always something extra if needed down payment/monthly payments etc.. The biggest benefit was being more accessible via mobile devices which allowed us greater flexibility than before where people could only access services by attending office hours / scheduled appointments timesetc.