Tit-for-tat kicks in. It's fine for smaller files to just jump peers with zero upload, but i reckon Meta would have found it challenging to download very large files without sharing. It's certainly much faster if you don't get throttled or banned by many peers.
replyWould you say that generally books would be considered a small file or a BIG file?
replythey'd most certainly go for very large curated collections like those of Anna's Archives, we're talking about 10s or 100s of TBs per archive
replygoing 1 by 1 would be quite the exercise in itself considering just how much variety of formats, styles, crap added in the files, random password crapware, etc etc you find for anything other than the most trendy stuff