Note 1: In my Zadroni reports, I don't give reasons why these things work.
That would be mere guesswork.
These are usable, successful, "working today" techniques - no theory, no guesswork - and ALL are based on many hundreds of tests.
And, hey, the results are always what matters, not the reasons, yes?
Note 2: These video courses are the ones that I use to train staff and outsourcers in my own businesses.