Are the review copy and sales copy can be interchangeable? I mean they are very closely related, then why not?
Usually No. But it depends on the copy types.
They might have some common features but that doesn't mean that they are interchangeable.
They have different purposes.
A good review copy can be used as a sales copy too. But that doesn't necessarily mean that one should do it.
Actually I have fine review copy that can promote the product quite well. I have tested it. It works flawlessly. So, I was wondering whether can it be turned into a sales copy or not. I have sent PM to all of you guys. Please check. Its a short version though.
Look you don't have to PM anyone.
I think you know the answer here already. A few tweaks to your copy and it will do just fine.
So, why don't you just go and give it a try.