YouTube Annotations can now click through to other sites

YouTube Annotations is about 2 years old.  It's a system that video uploaders can use to direct traffic to other videos, and has been used in lots of fun ways, including 'choose your own adventure' games like this one by Samsung.

Now YouTube are letting a few partners send traffic through to other sites.  This is potentially huge - for example click on a film trailer to buy tickets, or a DVD, or even click on an item of clothing to buy it.

These don't work embedded, but have a look at this example on YouTube itself.  Click on the buttons at the bottom of the video.