Take a look at the bookends on this new chart from Marketing Charts:

According to a new study by TubeMogul, Brightcove, and DynamicLogic, there is some modest growth in the percentage of YouTube videos that carry ads.  And though companies like Proctor and Gamble have caught some attention for online ad strategies that marry entertainment value with branding, still under 5% of all YouTube videos are themselves ads. Marketing Charts shares some of the findings:

Breaking out ad content by type (not counting YouTube’s homepage), about 93.5% of ads are 300×250 display ads. Another 5.5% are pre-roll, and slightly less than 1% are overlay.

In addition, content produced by YouTube partners is on the rise (growing more than 20% in six months) and content that actually consists of advertising is slightly up, but still represents less than 5% of all content viewed.

And just in case you have any questions about what consumers you are connecting with via YouTube videos, here's a not-so-surprising age breakdown:

Okay, it is a little surprising when you look at the far right.  Who are these 106-108 year old YouTube viewers?  More likely this represents some sort of self-report error.  Read more here.