Although I had originally posted this in US I was wondering how airlines in general do this.
I see that often times people build a MR around a great fare they have found. I realize that fares can be loaded any day or time.
Is there a better time/day than usual to find ridiculously low fares that have been loaded incorrectly, or is it like finding a four leaf clover- just keep looking and you may get lucky?

Thanks Mike