This is a brief introduction to a vast subject. Technical analysis, as opposed to fundamental analysis, includes analyzing charts and technical indicators like RSI, MACD, moving averages, etc. It has its uses if the trader or investor is aware of its good and bad points.
Subscribers are encouraged to do more research into this technique before using it with your capital. Just like any other methods, it is useful to deeply understand its strength and weakness.
One weakness is that its interpretations can be affected if you draw the same charts on a different scale, i.e. arithmetic or semi-log scale. Another potential weakness is that the price and volume of a stock can be manipulated so as to give certain patterns or readings for the other traders.