Shortened Link

If I shorten an Affiliate link with my own custom bitly domain, will the affiliate know what link the traffic came from or just the source of traffic

Example

The website is Yahoo.com, and I shortern it to Newhits.com/awewae or whatever, will they know the link I used to get the traffic? Or they will only know where I posted the link for example like Twitter.

I dont think it is possible to track the link...

Did you ever find out your answer? I am curious on this question as well.