If you have a lot of time to copy data between systems and always do it without error, then there is no reason to integrate your system. If, on the other hand, you are not a robot and you have other things to do than updating multiple systems with the exact same data, you might want to consider getting an integration between your systems.
If the system you usually update can expose the data in a secure and predictable way, you can also start being creative with what you want to do. Perhaps you want to integrate it with a dashboard systems, so your sales department can see the current top dog? When you start seeing your systems as small individual pieces you realize that you decide what the final image should look like.
A lot of different types of integrations exist. Not all system support all types, but a lot of established system provide at least one method of exporting from the system and importing data into the system. At InterOps we are able to use any of these methods to make your life easier and your work more productive.