Before the 1970s, movie merchandising was in its infancy, but then George Lucas changed everything. He negotiated to have his fee cut for writing and directing Star Wars - in return for the merchandising rights.
Lucas set up his own film studio on the back of the phenomenal sales of everything from action figures to lunch boxes and light sabers, and set movies on a whole new path to profitability. Now it's unheard of for a major blockbuster to hit the cinema without its own action figures, t-shirts, cereals, fancy dress, games and apps.
The top ten movies and movie franchises that made the most on merchandising makes for interesting viewing.
10. Unsurprisingly, Cars made a small fortune. Toy cars were already such a childhood staple that adding faces and personalities was never going to hurt - especially when it meant children would want to collect them all.
9. Despicable Me was always going to make a fortune when you could plaster Minions on anything and make children adore them. Then, of course, there's the soft toy potential for the yellow fellows - and the odd fluffy unicorn - which has pushed sales even higher.
8. Transformers actually started life as a toy line in the 1980s, so unsurprisingly the live action franchise has spawned even more of them. Some would argue that these films are effectively 90 minute long toy adverts.
7. Toy Story was a gift to merchandise manufacturers, given that the main characters are already toys that we're desperate to own. The franchise also gave Mr Potato Head a new lease of life after being consigned to toy history for decades.
6. Harry Potter merchandise appeals to children and adults fans alike. Once you've invested in wands and robes, you can pop to Orlando or Watford for more of the experience, and boost the franchise's money-spinning potential at every step.
5. Batman is something of a toy fan himself, so it's no surprise that the franchise created such demand from fans who wanted the same gadgets and gizmos - as well as their own action figure so they could recreate the odd epic battle.
4. Jurassic Park tapped into the never-ending childhood fascination with dinosaurs. The movie enabled kids to splash out on their own herd of dinosaurs for a showdown in the toybox.
3. Frozen breathed new merchandising life into the Disney princess lines. Everything from Olaf toys and games to Ana and Elsa outfits and accessories have been on Christmas and birthday lists since the film first emerged, and shows no sign of abating.
2. Marvel has been around - and spawning action figures - for years. The new films have meant many more ranges of the toys - as well as their own fancy dress costumes, backpacks and clothing lines. The never-ending stream of characters means there's always something new to collect, so the cash keeps rolling in.
1. Star Wars was the first and remains the most lucrative of them all. The franchise is top of the pile - and isn't set to go anywhere with the new films promoting another spike in the sales of light sabers and action figures. Clearly no collection is complete without a BB8 or a Rey nowadays.