Ramit Sethi is probably the most successful financial blogger of all time. He has more than a million views a month and his company makes easily $5 million a week. I must admit that I simply could not stomach his material because too much emphasis was made on bargaining.
However, any write-up on how he succeeded would be something that should be worth reading.
a) How tactics become commoditised
If you understand the timeless principles, you would always be able to come up with refreshing tactics. However, relying on a tactic may make you some money on the short term, but these tactics eventually get commoditised.
This is easily illustrated in investing.
Dividends investing is clearly a tactic. Finding a stock with a high dividend yield and sustainable cash flows is a useful tactic to make above average gains. This can be proven by backtests on Bloomberg.
The principle of ......