When we first launched BuildRedirects this was always an option we wanted to implement, however, we needed time to make sure it was done properly. As of today you can now add customized domains to your account so your links no longer have to use the sub domains we initially gave you. Customizing your domain is great for branding and also for inboxing (for email marketers).
We felt this addition was an absolute must have for our users for many reasons. Now you can easily use your links on Facebook, your emails and even Google Adwords without any issues whatsoever. We made it super simple to add a custom domain, and we even still do the hosting for you!