Joined: 09 Jul 06
08 Sep 14 2:53 am
We used to put P.Ses all over the place, because of the assumption that people would scroll all the way to the bottom of the page to figure out if the rest of the content was worth reading (and to see the price, when it came to sales pages).
The idea with the P.S was to try to ram home the most important and exciting things in the email to either encourage the reader to go back up and read the rest of it, or as a last ditch attempt at getting them to click something before they run away.
I haven't seen a great many P.Ses on sales pages anymore (I might be hanging out with the wrong crowd). I do see them in emails though, and I would use them to give readers the TL;DR (too long; didn't read) version of the email -- especially if it was a very long email. I wouldn't bother with a short email.
You could put your affiliate link in there, absolutely. If I were you I would test it. If your mail client lets you split-test your emails (send 50/50), try one version with a P.S and one version without. See if it makes a difference in the clicks.
Every list will be different, so there's no hard and fast rule. You just gotta test.