Book Ends/Advertising

Note that some Book Ends can be spoilers, so beware.

Examples of Book Ends in Advertising include:

The Montana Meth Project has some chilling public service announcements, with these two having the Book Ends. The first video shows a girl trying meth with her friends, saying she's only going to do it once. Cut to the next scene, where she uses meth again, still saying it's only once more. This was repeated a few more times, with the girl getting worse by the use of meth. At the end, the girl dies on her bed. Her younger sister then takes some meth from her older sister's jean pocket, saying she's only going to do it once.
- The next video shows a young man trying meth, also saying that he'll only do it once, as he doesn't want to be like 'That guy', a meth-addicted psycho, which scarily resembles him. He then tries meth once again, also with the same promise. Repeat a few times with the man getting more addicted, and he ends up being exactly like 'That guy'. In the end, a young girl buys some meth with the promise of only trying it once, as she doesn't want to be like 'That guy'. Which is obviously the guy before.
In a similar vein, an Australian alcohol awareness advertisement opened with a father asking his son to get him a beer at a party, followed the son's descent into alcoholism, then ended with the son as an adult, asking his son to get him a beer at a party, with the implication that his son's life would follow the same course as his own.