If you’re curious about how this works, try selecting some text from anywhere on our blog and pasting it somewhere. Rich text editors (such as most WYSIWYG HTML editors, or Gmail) will preserve the hyperlink but the text will also show up in standard plain text editors as well.
As a creator and contributor to the commons, you have the right to attribution (all six of our licenses require it), so why not make it easy for your audience to automatically provide it?
And don’t worry, the extra markup is just text. Nothing about Tynt’s tool forces reusers to do anything, its merely useful additional information providing proper attribution and license notification.