OK, so I am right now in the process of changing all of my product pages (for 1 product) from .php to .html. I guess my question is, I shouldn't have to worry about notifying my affiliates or anything because of the fact that each hop link goes through clickbank.net, which intern points to the home page without an extension (like www.productsite.com without the .php or .html, etc.) So it doesn't matter what extension I change it to, It will all be the same? All I need to change in CB is the thank you page URL, correct? I am asking this because I finally got a well converting product and I want to be sure not to make any idiotic costly mistakes while undergoing this change. thanks!
But why would you do that? Having your page in php is much better, even if you dont use any php code you can still have a page in php with normal html on it.... So then in the future, if you want to do a script you dont have to change the extension of the page back to php.
I'd either do as digitalkev suggests and hide the rename entirely or put 301 redirects so that old urls will redirect to new ones. In theory if you don't do that affiliates will not notice but you never know and the last thing you would want is to have an outraged PPC affiliate on this or other forum lamenting about his/her lost $$$. I'd also announce it in your affiliate section beforehand. It's nice to keep things nice.