Why do some Funko Pop lines like Marvel or Star Wars outsell others consistently?

[Shiek]

It's very obvious that some funko pop action figures like Marvel and Star Wars usually outsell every other brand that is in the market. I wonder what could be the reason why that happens? Maybe it's because of how popular Marvels and Star Wars franchise have been for decades?

 

[Axel]

Marvel and Star Wars are very popular brands. This is why they are doing very well in their movies and TV show's department.