While looking for a new video game to buy (yes – I am a nerd) I came across this which shows an excellent use of YouTube:

At the end of the video there are 3 embedded links – “want it”, “hate it”, “unsure”.

When you click on whichever one it then takes you to another related video. So if you click “want it” you go to the Red Steel 2 Debut Trailor (Want it) page:

You’re then prompted to say why you want to buy it in the comments.

Given that a couple of the ranking algo’s for YouTube videos are both views and comments this gives excellent CTA’s and can help towards good video rankings!