If these strategies would be working so well, Zacks would not be selling their service, rather be betting the farm on it. There is no easy and sure of making anything over the risk free rate...
Well, not exactly. They are not selling a system they are selling a data filtering database as is Reuters. Except, Reuters clients are hedge funds and other institutional clients not retail. I'll agree that the quality of Zack's is way lower than its institutional counterparts but they are both in the same game. I am very critical of the snake oil guys who sell trading systems. These guys are selling data and suggesting various ways of filtering that data. Admittedly the latter steps into the area of selling a trading method somewhat. But don't confuse them with the likes of Oliver Velez, Felton Trading and especially "Best Choice Systems" - now that's pure snake-oil.
I bought it a few weeks ago and and not sure how much use it is. I like the convenience of it's snapshot. Like other posts I wonder about how much revalence there is to this unusual market that isi all over the place. The salesman sounds like it's the only thing you need for 60% returns yearly. I just don't see how the market for the previous 5 years can be backtested for an idea about the current market.