What we've found is that when a client has our company's software on one of the servers in their network, sometimes they don't want to give us access to their network to maintain our software.
The other use case, which is a little bit weird, is that all of our clients are in healthcare so they are very particular about who gets into their network and who has access to their network. We have TeamViewer host clients running on devices, some wired in offices, some connected to WiFi or even cellular, and we use it to get quick access to the devices for technical support.
