Originally Posted by plaster

It's a passive link. It means that if a cookie has already been set, yours, that link won't override yours. It's meant to assign no affiliate sales to one account inside of NATS.

They are not shaving sales by that link.

The question though is why are no $4.95 trials converting to full memberships? Surely they don't ask the new trial member if they want full membership after trial...
It is statistically impossible for no trials to convert if the number of sales is in double digits. I would put 10 trial sales, and all cancel and/or fail rebill, at about 1:100. Higher number of sales, exponentially more impossible for nothing to rebill.