You must first enter the complete url of the affiliate's page who sent you here. The web address will look something like this:

Contact us & we'll send you the correct website address.

If you like, include any questions or comments and your website url.
We'll take a look and best advise.

We do this to protect our affiliates from losing out on a commission they're entitled to. 
No one can order unless through an affiliate. You'll receive this same benefit should you wish to resell our service.