I could work remotely and on my own time. This worked wonders when I already worked another job where mostly had to sit at a desk waiting for phone calls, so that I could effectively work multiple jobs at once.
Cons
I don't think anyone would claim the job to be intellectually or creatively stimulating. Also, the work sometimes didn't exist to be done, so potential income could be very erratic. And it can end in an instant, without any warning.