If the investor doesn't understand the risk... I guess that is how a signal provider would maybe stop that in a way, but you can always rig a martingale into an ea with just more orders on currencies.
I personally like MARTINGALE, however, it isn't for everyone and I do only 1/10 of my reserve. I can easily get out of it. To get 30% per month is wishing for trouble... :)
Grid traders, martingales, this approach, that approach, I guess I haven't seen a whole lot that works well in FX yet. So far scalping futures has been the truly only less risk option to make a quick buck for me. I wish they had stuff like this for futures! :)
Be Open, honest and ethical and all the $$$ you want will come. (hint hint)