Highest grossing film

After reading several lists online about movie ticket sales in theaters versus how much they cost to make, I found the movie making business is much more profitable than I previously thought. I found that there were several films, including avatar, that actually surpassed $500,000,000 in sales. This is a crazy feat considering many tickets cost only $8-$12 with profits going to the theaters as well. I found an interesting article in the week which found that many of these all time most profitable lists are only partially correct on which film actually earned the most. The article can be found through this link (http://theweek.com/article/index/263552/why-avatar-isnt-actually-the-most-successful-movie-of-all-time)
The article explains how many of the top grossing lists don't actually adjust for inflation which only makes them partially correct. For instance, if a movie was sold last year for $15 and 20 years ago was sold for $10, then the most recent movie would seem to be the most profitable. But say you had $10 10 years ago versus now, that $10 could have bought you a movie before, but not now. This goes to show that even though the profits are higher in numbers today, the actual buying power of each dollar would also drop. So for most cases, the older movies with relatively high profit margins are not accurately represented on these lists because most don't adjust for inflation. If you find lists dealing with profits, costs or other financial measurement interesting in regards to the film industry, please comment below. Thanks for reading!