Hey Steve - we don’t have any analytics on this.
That being said, you’re bound to see a higher conversion rate using your own Custom Domain. The unbouncepages.com URL is really just for testing your pages. As soon as you’re ready to embark on your marketing campaigns you’ll want to use your own Custom Domain.
Why? Using a Custom Domain is advantageous for four key reasons.
Google will not index your pages without a Custom Domain. Adding a Custom Domain means you have the option of Google indexing your pages - they’ll be searchable.
With a Custom Domain, you can add Page Metadata.
You can use your pages with your Google AdWords and PPC campaigns (Google won’t accept the unbouncepages.com URL).
Your own domain will always be more inviting. Your URL should be indicative of your brand and your product offering. Leads may be confused by the fact your pages say unbouncepages.com, when you’re advertising something completely different.
I hope that helps!