The referral ID is on the step 3 bookmark area. When you were at step 3 in zeriouz, it asks you to boomark the page so that you can get your codes again at a later date. If you didn't bookmark that area, you've likely forgotten all about it and have little recollection of where it is. In such a case, you can get back to that page by using these instructions:
http://www.zeriouz.com/edit-partners.phpThere's a link on the front page of zeriouz called:
"I Lost my Link Code!"
That's how you get to the above page.
Once you are in step 3, your referral URL is under the tab: "HTML Code".
That's the URL you need to get people to join under. It's the same URL that "Add Your Link" takes you to, on your website.
Also, if you didn't bookmark that page (Step 3) last time, please bookmark it this time (as it asks) and it will save you a lot of trouble looking for it later - because all your codes are in there.
And yes, if you want to use a short URL service for this URL to post it in chats or emails, it wont hurt anything.