Bloomberg is also aggressive in retaining customers. A few years back, there was a scandal where Bloomberg News reporters used Terminal data to see that a target of their news story had not logged in for a bit and wrote about it. Since this was breach of trust between the two parts of Bloomberg, many of the banks starting looking into alternatives for BBG chat, and Bloomberg responded by offering the banks (their existing customers) many discounted terminals. Which seemed to have worked since the scandal died down and their chat is still the leader in wall street communication.
According to https://qz.com/83445/what-bloomberg-employees-can-see-when-t... , all Bloomberg employees could see when a user last logged in (like "w" in Unix), transcripts of all chats between the user and customer service (these chats are triggered by pressing F1/HELP twice, as other comments have indicated), and how many times the user used specific functions over the last 30 days.