great thread
one thing that has been discussed is conversion ratios suddenly going to shit.
from my own experience pushing my own paysites (no affiliates) - conversion ratios are very stable. they're always changing, but it is always extremely gradual (as long as everything remains the same ie: content/design/etc).
i've never seen my conversion ratios ever make a big jump up or down, unless something was modified with the sites (just my personal experience).