Pixie. I think trend for plastic drink bottles came, when the deposit scheme for pop and beer bottles stopped.
When I was a kid, a discarded pop or beer bottle meant money to us kids. At the time, my parents had a small sweet shop, and I can recall the Corona lorry calling every week, delivering fresh pop, and taking the crates with empties away again.
The great advantage of plastic is that its many times lighter than glass and much less likely to break or leak, which must be another important factor in its universal adoption.
Here is an interesting link from BBC Wales, which many of you may have missed :::
http://www.bbc.co.uk/news/av/uk-wales-north-east-wales-42798408/milkman-inundated-with-calls-for-milk-in-glass-bottles