why no worldwide box-office instead of USA box office

I understand your answer to a degree but there is a problem without having the option to see the highest grossing movies worldwide. For one it is inaccurate to state these movies listed were the "Top Grossing Films of 2013" when it is only domestic information. Take for example, your last years list states Catching Fire was the highest grossing film when in actuality Iron Man 3 was with Worldwide totals exceeding the 1.2 Billion mark and Catching Fire made 848 Million. Worldwide totals can't be off that much to say that Catching Fire made more money. I would just like to have the option to see Worldwide Totals as a drop down option or another page link because in the end the most popular movies will have a Worldwide release information. It's just one thing but as a constant user of IMDb and Box Office Mojo I know myself and others like me would really like to be able to see that information easier than going back and forth through the individual page links. Thanks so much!

I'd like to be able to sort by worldwide box office when searching. Otherwise it is pretty pointless.

For foreign films (for example, for a UK film such as "God Help the Girl" http://www.imdb.com/title/tt2141751/) US box office is not very meaningful.

The information in Box Office Mojo is of little help. The term Domestic is used to refer to the USA box office (incorrect word use for a UK film). Furthermore, the total box office on the summary page is listed as the same as the Domestic box office. There is no world-wide total (which would be around 3 times the USA box office).

In addition, the Charts section in B.O.M. lists rankings without totals. For example, one line is "Top Movies in the Past 365 Days 347". However, this should be shown as 347/682. The same for US and Worldwide rankings (Domestic is listed, but not US and Worldwide).

By the way, the word Movie is almost exclusively a US term. The International English equivalent is Film. Even though professional movie cameras have been digital for over a decade, we (in the US) still say a movie will begin filming on xxxx/xx/xx date (the terms lensing and recording have not caught on).

I think as Dan points out there are a number of factors. IMdb gets its box office information from Box Office Mojo which has reliable domestic box office for current films and past films to some degree. A similar clearing house for reliable worldwide box office is even harder to come by and the data becomes suspect the further back in time one goes. Yes, ideally worldwide numbers as the primary box office or equal standing with North American domestics ones on IMDb would be great. But, the numbers to have an value must be complete and accurate, which wouldn't be the case.