Posting links (external or internal) on Campfire is different to how you post links on Facebook.
Many members are used to the Facebook way, tending to paste the URL link, wait for the link and a link image to appear, then, to tidy up the post, delete the URL.
You don't have to delete the URL on Campfire; the code does it for you!
So, paste your URL link, add a descriptor (we'd always encourage you to do that to set the context of your post), then post it. The post appears without the pasted URL.
As member Bruce Bickerton says "A-mazing."