Youtube Placements for SAS3.0

Hi,
As a workaround, I set up my audience as Business Services and a few other similar cohorts. However, when I check ‘placements’ the ad is being shown in places that I would not expect i.e. kids tv, Peppa pig, chinese channels etc.
I am struggling to understand what the selected audience has got to do with all of these non-relevant channels. I thought that my ads would only be displayed as an intro to videos related to the audience selected i.e. Business Services - so what has the likes of Peppa pig got to do with this?
Could someone please explain?
Also can someone please advise if the way you tube ads work is that they are displayed at the start of someones video and I only get charged if someone watches it for 30 seconds?