I like how easy it was for me as an agency user of Replay, to connect with their support team via chat/email when something went wrong during our test runs or implementation process. They were always quick at responding (even over holidays!), even if they had just finished working all night! We have been using replay internally since we started up about 6 months ago now - great tool which has helped us understand what content works best across different channels so far!! Nothing really; everything worked well but i would say most importantly you need someone who can help set this service up from scratch once installed into production environment. Make sure there's enough staff available within any given department such as Production Support / Technical Team etc., otherwise things will take longer than expected due to waiting times between departments getting connected together. A better understanding of channel performance data helps drive future strategy decisions around where you should be focusing.