Ah does that explain why some kids/daytime programmes on ITV didn't have any (or many) adverts on them back then Sparky?
Yes certainly.
All advertising was from the outset (and still is to a degree) regionally based.
Basically, each region sold it's own Advertising space, and could charge different rates depending on what time it was shown, how long for, and how popular the programme was.
For instance - advertising during "Sunday Night at the London Palladium", during the Winter would cost at least 20 times more per second than advertising between (say) "Lunchbox" on an afternoon weekday.
There was also seperate rates for B&W and Colour Adverts too.
Most Childrens programmes didn't have a Part 1 / Part 2.
Any advertising, if any tended to be between the programmes themselves. They wouldn't be presented in a "Package" (under a banner like CITV)- they'd just be scheduled at a particular time of day, and broadcast the same way as other programmes.
The only "Package" if you like, would have been the BBCs 'Watch with Mother' - which was rebranded 'See Saw' in the early 80s.
It wasn't until the late 70s ITV - packaged Kids programmes under "Watch It!" and then "CITV" in 1983.
I think the ITA/IBA had strict rules regarding advertising during programmes aimed at Children. (Far far different from that today).
Advertising during "Schools Programmes" was strictly forbidden.
If anyone remembers (I have only seen them in archive form) - during the late 50s and early 60s; ITV used to show "Advertising Magazines".
Which were 15-20minute programmes funded by advertisers - usually for Home Appliances/Cookers/Hoovers/Washing Machines etc.
They would give a (tacky US TV style) presentation of the items and show them in use - not far off from such things like QVC or the shopping Channel.
These were outlawed by the ITA around 1961/2 as they were seen as product placement.... ahem....
As a foot note and example:
"Tiswas" started in 1974, only broadcasting to the ATV region in the Midlands.
They had very short advert breaks mainly consisting of Local adverts, and perhaps the odd major advertiser.
By 1977, "Tiswas" was carried by about 3 or 4 other regions (Granada / LWT / STV I think), so the advertising rates would have shot up and the Ad breaks got a little longer.
By 1979/80 - it was just about fully Networked - and more National Advertisers invested at a target audience.