Research: Independent films

I have decided to research examples of independent films and the features of them to decide what I'm going to classify my film as and how it will impact on the trailer. (For example whether it would be promoted as a conglomerate film or independent film)
Independent films are sometimes known as indie films.

What are independent films?
Independent films are those which are made entirely or mostly outside of the major film system. They are also produced and distributed by independent film agencies. Independent films are sometimes different in content and the creative way in which the director's artistic vision comes into fruition.
Independent films often have lower budgets than those produced in the major studios (for example by conglomerates). This is because they have less resources and are those involved are frequently not as well known in the industry.

Categorizing films
In the 1930s, there was a kind of pecking order that evolved within the film industry. At the top of this pecking order were five major studios: Metro-Goldwyn Mayer, Paramount Pictures, 20th Century Fox, Warner Bros. and RKO Pictures. These could usually make highly successful films with larger budgets. Many of these names remain prolific today. Then there were 3 smaller but relatively well known companies: United Artists, Columbia Pictures and Universal Studios. Lastly there were those known as Poverty Row. This defined any small company who managed to move up the ranks in the film industry. Examples of these are Republic Pictures and Monogram Pictures.

Examples
Notes on Blindness (2016) is a documentary film produced by Archer's Mark, in association with Fee Fie Foe Films and 104 films, co-produced by Agat Films and CIE and ARTE France. It was written by and directed Peter Middleton and James Spinney.
After losing history sight, just before the birth of his son, John Hull was determined to know as much as he could about blindness so that it didn't get the better of him. He began keeping an audio diary. Throughout three years, John recorded over 16 hours of material, discovering more and more about the interior world of blindness.The documentary charts his experiences of life, encompassing love, loss and much more.
The film premiered at the Sundance Film Festival 2016 as well as winning the Special Jury Prize at the 59th San Fransisco Film Festival and the Wellcome Trust Innovation and Storytelling Award at Sheffield Doc/Fest.
A Virtual Reality Project premiered alongside the feature film at the Sundance Film Festival 2016. This is called Notes on Blindness: Into Darkness.

Gasland (2010) is a political cinema documentary written and directed by Josh Fox. The film focusses on communities in the USA affected by natural gas drilling. More specifically, a method of horizontal drilling into shale fractions. This is referred to as hydraulic fracturing. The film is regarded as a key mobiliser in the anti-fracking movement. Gasland is Fox's first documentary and second film. It was edited by Matthew Sanchez and produced by Trish Adlesic, Molly Gandour, and David Roma alongside Josh Fox. It is distributed by New Video, Group/HBO/ International and WOW company. The duration of the film is 104 minutes, and it was first shown at the Sundance Film Festival on 24 January 2010. The film received largely positive reception, with Robert Koehler of Variety calling it "one of the most effective and expressive environmental films of recent years". 
However, the film also gained some negative criticism. There is a web page listing factual inaccuracies with the film. This is launched by the Independent Petroleum Association of America. 

Gasland (2010) trailer