It's Christmas, but no company wants to let that get in the way of a money-making opportunity, and schools programming was definitely that.  Even though it carried no advertising, it counted towards the averaging of advertising minutes later in the day, thus benefiting the companies.

The reason the ITA allowed this was simple.  Encouraging the companies to do something they didn't want to do was very difficult.  The ITA could write it into contracts, but the opportunity to do so didn't arrive that often (1964, 1968, 1974, 1982).

So they used the fact that the system was inherently capitalist against those companies taking part - in other words, appealed to their greed.

The companies, left on their own, would probably have not produced more than a token amount - if that - of schools, adult education, religion and news programming.  You only need to look at ITV's schedules now for the proof of that.  So the ITA offered a very tempting carrot.

Under the terms of the Television Act, such programmes could not contain advertising.  So the ITA offered a compromise - produce and carry such programming and it will not count towards total hours on air.  But it will count towards total advertising time - increasing the minutes available to sell.

The success of this policy can be seen not only in the scheduling of the programmes even during school holidays but also by the quality of the programmes themselves.