So it really depends on how many people at what point in the "food chain" are around. If it's all sheep who follow active trends, the method wins. If it's all people trading on fundamentals and ignoring you, the method loses.
+1 There are many profitable methods to trade somebody else's market manipulation and better still unlike the market manipulation itself these methods are perfectly legal.
In some regulated markets, its illegal
http://en.wikipedia.org/wiki/Layering_%28finance%29
Layering is a form of market manipulation and in many markets is in fact illegal. It is also a very good example. So I am a long term investor and I am looking to build a long term position in an illiquid market. I sit and wait and when an ask wall shows up I buy it at market. How is this illegal?
Now if this ask wall was part of a layering market market manipulation there is a good chance that the manipulator can get caught in a nasty short squeeze and provide me with additional profit.