Finding Low Airfares Day of the Week

I saw a recent article at the Middle Seat blog that talks about Wed morning probably being the best day to find cheap airfares. Some credibility is given to this notion by at least two of the major airlines that do publicize their sale fares starting Tuesday "e-fare sale" (United) and "Net SAAver" fares (American) on Tuesday afternoon.
If this leads to other airlines scrambling to match fares, then Tuesday night/Wed morning does seem like a good time search for fares. Of course, in today's algorithmic world, you do not need to sit in front of the computer the whole time. You can set up your preferences on sites like Yapta, Farecast or other airfare tracking websites and just wait for the good news in your email box. Then you need to act quick and snag the fare. I have had positive experiences with Yapta helping me get into a fare that went down for a week or so. I bought it then, to see it go up afterward. I have nt had an occasion of an airline fare going down in price or going into discount. In such cases, you could apparently get vouchers from some airlines, like United or Alaksa/Horizon Air, but not with some others like US Airways and others, which charge 'change' fees from 50-150 dollars, wiping out any savings.