Hi
Normally you'd still get the credit. As far as I'm aware, Clickbank operate on a "last person who recommended" gets the sale. So providing you were the last person to send the referral, all should work OK. The list owner is unlikely to set a cookie for themselves in any follow up email. Longer term, that would work to their detriment as most affiliates have at least a rough idea of whether their efforts are making them any money (especially those who use pay per click ads).
That said, there are some issues with Clickbank cookies not being set if the user has run some of the anti spyware programs. Some of these treat Clickbank, Commission Junction and other networks as spies. Pain in the neck but just something to be aware of.
Definitive answer: the best way to find out what's happening is to sign up to the email course on your own Clickbank link and see where the link takes you. If you're still flagged as affiliate (and haven't reclicked your Clickbank link in the meantime) then all is working as it should.
Trevor
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