I get an immensely pleasant feeling out of this.
I ended up resorting to this because 95% of all the phone calls that come into my extension are salesman spam or people looking to get help out of me without going through the proper procedures (read: obtaining a helpdesk ticket and waiting their turn). I grew weary of having to listen to the phone ring four or five times before it was sent to cover, and I discovered that even when I had the ringer volume turned all the way down that annoying sound still persisted. By having every call go to voicemail I have taken control of things in a manner that I approve of: I am now able to pick and choose whom I call back, thus weeding out the salesmen and leeches, and allowing me to perform my job duties in a much more efficient manner. Why is this such a big deal? Well, it's really because my employer won't give me a display phone for my desk (My department is the only one in the entire office building that does not have display phones. No, our phones aren't old, they're the same model as everyone else minus the LCD display). The rationale behind refusing my request for a phone with a Caller ID display? "Oh, we're concerned that you'll pick and choose whom you take calls from."
Isn't irony delicious?