"How does this help you? Well, using these metrics, you can increase your videos' view counts and improve your popularity on the site. For instance, you might learn that your videos are most popular on Wednesdays, that you have a huge following in Spain, or that new videos that play off previous content become more popular more quickly," suggests YouTube's blog.
The analytics data is really basic and doesn't include a lot of interesting information like the sites that embed your videos, the most important sources of traffic, how many people view the full video or play it again etc.
To find your video stats, go to your YouTube account and click on "About this video".