The long and short of it is that whatever you include should accurately represent the majority of the content. If people bitch about not having thumbs for evey file then that's annoying, but if they're just saying they wish they were included then that's something else. It's all about the tone of the message, and it's worth remembering that the tone of a written comment can be misunderstood.

Like @frostycab I have very rarely (not absolutely certain that I have never) left negative comments regarding thumbs within large torrents. I have, on occasion, uploaded those thumbs myself, when I've decided to download the full torrent and found them missing.

Images in a description is a different thing. "At least one good quality image" is a requirement, not a suggestion, and I see no reason why anyone meeting this very simple, basic,rule shouldn't be called out for it. Though relatively politely, of course.

i'll never understand how someone would go to great lengths to create an amazing collection with names, titles, dates, only to sell it short in something as easy as providing previews.

when you provide previews you increase the number of people who will be interested in obtaining that collection.

when i see a torrent with hundreds of files and no thumbs, all the effort you put into into are wasted because i will not be downloading everything to find out if it's something i'm interested in.

with thumbnails, people might decide to download only certain files, which already is traffic that otherwise you'll not get at all, but in most cases seeing the thumbs is enough to be convinced that everything is worth downloading.

why would any uploader want people to download mysterious files? i understand that one might think the content is really good so thumbs are not required, but after someone spends their ratio downloading it because they are curious or feeling lucky, once they find that it's not what they expected, there's no way to recover that ratio, in many cases.

when you're early to the distribution, sure, you can easily seed enough to recover, but after hours, days, when you're the only leecher in the swarm, it's not a risk everyone is willing to take.

i know that this is not an excuse to the aggressive and inconsiderate ways some members choose to express their discontent, but in the end of the day it's up to the uploader to absorb whatever feedback they get from the work they're putting, deciding if it's worth the change, or just stop posting at all as a punishment to the complainers.

i only speak to myself that whenever i upload anything there will always be thumbnails, even if it's just one file. this is something that i value when i'm choosing what to download so i could never simply decide to not do.

long story short, either if you just want to be helpful, or if you are doing it for the upload traffic and the bonus points, the thumbs will only add value, increase the chance of it being downloaded by more people and make them be more appreciative of your efforts.

If, however you mean images contained within the upload then that's another matter. I never look through the previews as I rely on the listing pics, but I do believe that when a torrent is quite large and contains dozens or even hundreds of videos then "best practice" is to include a folder with comprehensive previews. The thing is that making them is not a labour-intensive operation. Thumbnail makers nearly always have the ability to batch-process files so that can just run in the background or while people are away from the computer, and the filename structure usually matches that of the original video, so no renaming required. The size of collections has grown to the point where it really does restrict those who struggle to keep their ratios up.

if the torrent is small size like, 1 GB and under then i wouldnt care but if its 10GB+ then thats a problem for many ppl