I had a difficult time convincing management that it was worth spending 30 hours developing a script to automate a task that normally takes 10 hours to do, even though we do that task at least once a week. Finally, I just ended up doing it on my own "free" time at work and showing it off in a meeting. I got chastised for spending the time doing it, but they were still impressed that the task now only took 5 seconds to complete. I ended up winning an award for it.

Unfortunately, that didn't mean I had less work to do. If you find a way to make your job more efficient, don't be surprised when management finds a way to expect more work from you.