That's because total box office gross is the truest measure of success. Theatre's don't keep failures on the screen long enough to gross a billion dollars. Movie studios make movies to make money. Percentage of total gross blah blah doesn't really matter. If a movie made only 10% of total gross on its opening weekend, by this measure you would say it is more successful than IM3. But what if that movie only grossed $50 million and was net negative? Is that objectively successful? Is it more successful than IM3?
If you can find a movie that matches this description, I will look into it.
Critical response is not an objective measure and neither is some list of worst comic movies of all time.
I agree, but a comparison between scores based on weighted reviews IS objective. Yes, all of the critics they sampled are just stating their opinions, but a weighted average is the best data we're going to get as far as critical consensus and we know that the same mathematics was used for getting the weighted average for both films. Therefore, if Spider-Man 3 got 59 and Iron Man 3 got 62, I can say that the films had similar critical reactions based on objective data. Furthermore, I can say that multiple respected critics agree that Spider-Man 3 is one of the worst superhero films of all time, and that is a fact, even if the content of the lists I'm citing are entirely opinion.
This list includes all sales from all movies regardless of year released so it includes a couple from 2012 and earlier like a re-release of Little Mermaid. Those movies not released in 2013 should be tossed from the sample. The list features many animated films for children, skewing the list further as children's movies sell like hotcakes. They too should be removed from the sample. The list measures all sales from 2013 but fails to recognize that not all movies were available at the same time allowing more time to accumulate more sales for movies released earlier in the year. This list should be sales against an average or sales cut off after X weeks but holiday sales can skew the numbers heavily. There is a good way of measuring this but I'm not a statistician so...yeah. What I'm saying is total number of disc sales over an arbitrary time is a bad way of measuring success because of various factors.
Just to head off a dumb argument, gross sales for theatres is different than gross sales for discs as discs are available forever and theatre viewings are not. Therefore gross ticket sales as a measure of success

, gross sales of discs

.
These are extremely flawed arguments for a variety of reasons. You make a logical contradiction when you say the list is unreliable because it can list the same film in multiple years but also that a films date of release can give it an advantage. If a film is released in December or something, you just add up the sales from that year and the next and compare it to the rank for the year it was first released. Also, why exactly should re-releases and children's films be removed from the data? And how do you decide which films are children's films and which are for adults? The answers to both of these are awfully subjective decisions for someone who's calling for objectivity.
Anyway, yes, gross sales in theaters are not available forever, which is actually why they are
less reliable for determining the quality of a film, not more. Ticket sales include a large amount of people who saw it just to have fun with friends or because of good marketing or because of faith built up by previous entries in a film franchise or love of a source material. By the time a film comes out on home media, they've already seen it or heard about it from others, so we can tell whether they thought it was good or not based on whether or not they buy it. From ticket sales, we can't tell why they saw it or what they thought of it.
You should try only using objective measures
I don't think it is debatable the Avengers boost brought more people to the theatres than would have otherwise gone inflating Iron Man 3's gross beyond what it probably should have earned, but to argue the movie was not successful is dumb. I thought Pocahontas Avatar was dumb as **** but you won't see me argue the movie was not successful. You are arguing against the numbers. If you want to win the argument, talk about the critical reception to the movie, but citing the numbers is a losing strategy.
First you criticized me for citing critical reviews because they are not objective, then you demand that I attack the film critically. That's a contradiction.
I also did not like Avatar, but I would never argue that it wasn't successful. Unlike Iron Man 3, Avatar didn't just do well at the box office,
it also topped home media sales for the year when it's DVD and Blu-ray were released. Furthermore, it's opening weekend accounted for just a little over 10% of its total gross, compared to Iron Man 3's nearly 45%. On Metacritic, Avatar's score of 83 handily outclasses IM3's score of 62. Finally, the production team behind Avatar were so pleased with the audience reaction that they are planning a separate trilogy based on the property, while Marvel quietly swept talk of Iron Man 4 and 5 under the rug after the release of its film.
So thank you for bringing up Avatar because it's a useful example for demonstrating that the metrics I'm using are really effective. Even though I don't like either film, I would definitely say Avatar was a success while Iron Man 3 clearly was not.
Iron Man 3 was not critically successful. Iron Man 3 was financially successful.
If you check my past posts, you will see that I have conceded this multiple times. What I am trying to explain is that, just because it was successful at the box office does not mean it was successful overall.