As a science-phile, i have to say...
1) anecdote does NOT equal evidence.
2) without a control group there is no evidence
3) without double or even triple-blind experiments - there is shaky evidence
4) numbers have to reach rather large values (think thousands or at least hundreds) of legitimate experiments to be considered statistically significant.
saying (even it is true) that i got awesome bud and all females from using an experimental light cycle with insert-hyped-nute-brand-here with killer seeds i got from some guy is NOT evidence. It is an interesting talking point and as others add there experience there can be a kernel of a worthy experiment but is not proof.
Sorry - i'll climb off my high-horse now.