As with all things, sometimes it only takes one moment to completely sell somebody on the idea. This is even more true with movies.
The whole idea of the marketing campaigns painstakingly put together to sell every single movie is to put butts in cinema seats and money in the box office takings. Without huge, hilarious, or heartwarming moments to flex their film's muscles, studios would be doomed to never make a profit on some of their fantastic properties.
Some films are hindered by the context surrounding them. They may be the umpteenth entry in to a long-running franchise, or they may just be big risks financially, so emphasising these perfect trailer moments is absolutely vital.
10. Fury Hijacks The Trip - Spider-Man: Far From Home
If it weren't for Sony's eagerness to push Spider-Man: Far From Home's marketing out prior to the premiere of Avengers: Endgame, this trailer could have been met with much more adoration and excitement than it was.
As fun as Spider-Man: Homecoming was, and as incredible as Tom Holland is behind the red mask of the wall-crawler, many fans were angered by the Endgame-spoiling trailer that confirmed that Peter Parker would be un-dusted and swinging back in to cinemas following his decimation at the hands of Thanos in Avengers: Infinity War.
However, any annoyance at this jumping the gun was soon swept away by the firing of another gun; belonging to Nick Fury.
When it is revealed that Peter's best friend Ned has been knocked unconscious by none other than Samuel L Jackson's one-eyed spy, all signs pointed to an exciting new direction for the high schooler, one involving espionage and the chance to step up from being a friendly neighbourhood Spider-Man to a fully-fledged, international hero.