Working from home works best for salary employees versus hourly. It's hard to verify the number of hours someone has worked so you need to trust your employees more if they are hourly.
I'm salary and I do work from home. When I went into the office, I would work my normal 10 hour day and then go home. Now that I work from home, I put in more hours because I don't have the travel to and from the office. That gives the company additional free work. I think I also work harder at home to prove that I'm actually doing something instead of just sitting around twiddling my thumbs.
The company saves a lot of money when the employee works from home. Office space is very expensive and our department showed a cost savings as people left the office permanently and surrendered their desk. If you still go into the office periodically and have a specific desk, you're not saving that money. They have been able to reallocate the space for other departments and they pay the costs.
I save on Gas but my electric bill has gone up.