Market Research - Product Placement

My target audience is aimed at school aged teenagers. What I am doing is analyzing all the channels to see who watches it/platform at different times. I am doing this so I can put up a 25-30 second advertisement which promotes Cyber-Safety. I need to do this analyzing so that I can find the right channel that most school aged teenagers will be watching at the correct time.

The most watched channels are:

1. Channel 4 -
Coming from me, as I am a school aged teenager, when I turn on the TV I would go straight to Channel 4 as I think its programs are funny and entertaining. Channel 4 broadcasts some very entertaining things such as Educating the East End, Alan Carr Chatty Man and Hollyoaks for example. But Channel 4 mostly aim there stuff at 15-35.
Advertising at breakfast would cost you £500. Advertising at daytime will cost you £1500. Early peak and late peak is where it starts to get really expensive. At early peak, it costs £4000, and at late peak it will cost you £7500. At night time, it will then drop back down to £550.

2. Comedy Central - 
From research I have found out that Comedy Centrals target group is the age between 16-34, and I quote, "with both men and women displaying a fondness for a good joke". This means it is not just aimed at one gender, but both.
To advertise at breakfast, would cost you £10. At daytime, that would cost you £80 because most people would be at work and school. At early peak and late peak is where it is most expensive at £450, that is because most people are home at this time watching television. Then at night time, when most people are sleeping, the price would drop all the way down to £40.
3. ITV 2 - 
ITV 2 employs a focus on American programming, such as Gossip Girl and The Vampire Diaries. In addition to this, it also airs repeats of shows from ITV, as well as spin off shows such as X Extra Factor and Britain’s Got More Talent. It generally targets a younger audience.
To advertise at breakfast time will cost you £400, and at daytime £800. At early peak it will cost you £16-00 because most people should be home from whatever they're doing. At late peak it will cost you £3000 because everyone should be home and watching television at this time. Then at night time, the price drops to £300.

4. E4 - 
Channel 4 caters to the younger, 16-34 demographic with a blend of American and British series. Its programming consists of Imports such as New Girl, How I Met Your Mother and Big Bang Theory, as well as British shows such as Rude Tube, The Inbetweeners and Skins.
At breakfast it will cost you £150 to advertise, and at daytime it will go up a bit to £300. At early peak the prices go up to £4000 and late peak it goes down to £3000. At night time, the prices drastically go down to £300 because most people are sleeping and not watching television.