This might be old news to you but was new to me.
I used tinyurl.com to cloak one of my links in an email promotion. I was mailing to a raw website of ours with my list so that my affiliates would get their due credit in commissions.
However I realised that if you mail a raw website link with clickbank payment links. Tinyurl will automatically credit the sale to an affiliate "viglink"
Just a heads up on this.