I am a complete n00b when it comes to making sites, but I have a little advice (because It will be probably ignored since it's too much work).
I noticed that some sites started to use 7-zip format (.7z) instead of rar and zip because it can compress even better than normal ones (www.hongfire.com uses it a lot..don't ask me what I download from there ;p).
It looks like this - the filed compressed in 7 zip has 80 MB, after unzipping it has 603 MB !!
What I want to say, instead of keeping manga in rar format, we could change it into 7-zip ( I also noticed that the newest rar program can handle unzipping 7-zip formats), so we could decrease the size of the files greatly.
...of course that would mean a lot of work - removing old archives, making old archives and stuff..and actually, 7-zip is especially efficient if the file is big (so it would work better on volume files, not on chapters).
But just consider it and acknowledge...
JPEGs only benefit from a marginal decrease in filesize when compressed into an archive. The difference between a zip, rar or 7zip would be negligible.
Also, all the downloads are taken from IRC, so they are already in the rar format, it would be far too much effort to unzip and recompress them.
I see - thanks for the commentary and for explanation :) Kinda knew it would be a lot of work from the beginning but still wanted to present the idea.