Films once spent months in cinemas before appearing at home, and now often arrive within weeks. The compression is driven by the cost of advertising rather than by any judgement about cinemas.
Awareness is bought once and decays quickly
A release campaign concentrates enormous spending into the fortnight around opening. That spending creates awareness which begins fading almost immediately afterwards.
Under a long window, the home release arrived months later, by which point the awareness was gone and a second campaign was needed to recreate it.
Shortening the window lets the home release use the tail of the original campaign. The same money is made to work twice, which is the entire argument.
Cinema revenue is heavily front-loaded
Most films earn the bulk of their box office within the first two or three weekends. After that, screen counts fall and takings decline sharply.
The later weeks of a long window therefore contribute relatively little revenue while blocking a release that could earn immediately.
Distributors reading those curves concluded that the tail was worth less than an earlier home date, and negotiated accordingly. The films most damaged by that reasoning were the ones that had always earned slowly.
Exhibitors lost the leverage to refuse
The long window existed because cinema chains could decline to show films that broke it, and that threat was credible while cinemas were the only route to an audience.
When studios acquired their own distribution platforms, the threat weakened. A studio that can release directly has an alternative that exhibitors cannot match.
The result was negotiated shorter windows rather than an abolition, with the length varying by film and by chain.
Not every film shortens equally
Titles that hold audiences over many weeks retain longer windows, because their tail is genuinely valuable. Family films and word-of-mouth successes belong here.
Films that open large and fall away fast go home quickly, since there is nothing left to protect.
The window is therefore no longer a rule but a per-title calculation, made after opening weekend rather than before release.
The consequences reach into how films are made
A short window rewards films that can be sold on opening weekend, which favours recognisable properties and large marketing spends.
Films that build slowly through recommendation have less time to do it, and a shorter run means fewer screens available for that process to work.
The kinds of film that depended on a long theatrical life have become harder to finance, which is a structural effect rather than a change in taste. Audiences did not stop wanting those films; the release calendar stopped supporting them.