John Gruber of Apple commentary website Daring Fireball has discovered the company behind those annoying copy and paste URL add-ons. If you've ever tried copying text from a website and pasted it only to discover additional paragraph breaks and a "Read more at http://example.com/samplearticle.html" sentence, you have Tynt to blame for it.
The pitch from Tynt to publishers is that their clipboard jiggery-pokery allows publishers to track where text copied from their website is being used, on the assumption that whoever is pasting the text is leaving the Tynt-inserted attribution URL, with its gibberish-looking tracking ID. This is, I believe, a dubious assumption. Who, when they paste such text and find this “Read more:” attribution line appended, doesn’t just delete it (and wonder how it got there)?
It certainly isn’t being appended to help the person copying and pasting the text. The person copying the text knows where it comes from.
We've encountered this situation more than once, and can tell you that it's more of a hassle than anything else because we always have to delete the extra text and line breaks. Read the full post over at Daring Fireball.