[slightwinder]

It's impossible to press a complex object into singular value. Everyone has different key aspects and you can't see from a single value which key aspects are strong and which are weak.

Read some reviews and critics to get a hint on the vibes and content of a movie and whether it matches your personal taste. IMDB has them both.

[pauljeba]

What about multiple metrics, which each can talk about specific aspects of why someone would watch a movie. I could then weigh these metrics as per my preference and choose the movie of my liking. Do you get it?

[slightwinder]

Sure, you can do that. There are sites doing this, many more did that in the past. Most failed at some point because the amount of work, knowledge and dedication for this to reach a critical mass of uptodate meaningful data is to big to survive longterm.

And in the first place you will be very busy to figure which metrics you want in the first place. You basically need a complete set of them before you even begin for serious, because otherwise you will invalidate all older entries if you add metrics later.

Thinking about, tags are popular today, several media centred-sites are using them to allow a kind of freeform-metric to describe content. Maybe with modern solutions you can do something machine learning-voddoo to extract tags from reviews and generate meaningful metrics for describing impressions of a movie.

[pauljeba]

You are very right, especially with the challenges in making it successful. Crowd sourcing or Machine Learning are the options I guess, each with its pros and cons.