To share the digital catalog to non- RepSpark users, you can create a global link.  This can be emailed and shared to new potential buyers.  The global link is not "shoppable" or clickable t=for the details within the product pop up.  

To create a global link, go to the set permissions within the drop down on the catalogs page.

Or, within the catalog display and editor pages.

Once within the permissions pop up, click "Generate Global Link."  This will crate a link to the digital catalog that can be shard.