I tested this service recently with a small file, and here is my review of the whole experience:
Initiation:I searched for a torrent on btjunkie.org, copied the download URL and pasted it on the website. I got a message that said: "Sorry, there was an error opening the file". I then downloaded the same URL on my computer using wget (worked just fine), and tried uploading it. This time I got an error which said "file is invalid". I realized that wget had changed the file extension to ".torrent.1", so I renamed it back to ".torrent" and uploaded it. This time the server accepted the file successfully.
Payment:The server checked the file size, and quoted me a price in BTC (which seemed quite affordable, IMHO). I paid the amount, and in less than ten seconds, the server had confirmed my payment. In other words, it proceeds with a 0-confirmation transaction, which makes for a slick user experience. On another note, I noticed that the server provides the same bitcoin payment address for every transaction, since the address already has a few transactions on blockexplorer. I also confirmed this by downloading a second torrent. This should probably be changed ASAP for user privacy protection and security. See this wiki page:
https://en.bitcoin.it/wiki/Merchant_Howto#Common_ErrorsTorrent download:I received a download status page, which just says "Downloading", but no progress bar or ETA for finishing the torrent download. I reloaded the status URL regularly until the status changed to "Completed." Since I downloaded a small file, I couldn't estimate the exact download speed. It was definitely around or above 1MB per second - could possibly be larger for bigger files.
HTTP download:After the torrent was downloaded on the server, it gave me a URL to download from. My torrent was a multi-file torrent, so clicking on the URL dumped me on to a web-server generated directory listing. I would have had to navigate through this directory listing and download each file individually, if not for tools like wget. Providing a zip file of the entire torrent would be much preferred here. Also, the download URL is not hashed or obscured in any way: this may allow users to guess the locations of other "popular" torrents for example. It also allows me to download the same file multiple times, and from different IP addresses. This will allow users to pay for a download once and distribute the URL on a forum, for example. I don't know if this will really be a problem, but you may want to think about this. As for download speeds, I'm connected to a 100Mbps high-speed university internet connection, so downloads from most fast servers go at 10 MB/s. However, I was only able to download my torrent from bitcointorrentz.com at 400KB/s, which I would consider slow.
In a nutshell, the core service works fine. There are a few rough edges here and there, but nothing that can't be fixed. I hope this feedback is useful for future users and to mjcmurfy for improving the service.
Thank you so much for going to the trouble to write that extremely helpful review of the site. Most of the issues you brought up I am already aware of, and am working hard on solutions. Apart from those few niggly things, the site is working as it should.
The reason why the site could not download your btjunkie file is because btjunkie employ certain security protocols, meaning that the "Download Link" you click for the torrent file is not the actual file itself. It does a subsequent redirect, then the torrent begins to download. I have noticed several sites have this authentication method, and I am not sure how to overcome this issue other than recommending that people download the torrent and upload the torrent file manually. Torrents from thepriatebay, however, work fine via CURL downloads.
With regards to the payment system, I am aware that all payments are going to the same bitcoin address. I am already in the process of creating unique wallet addresses for individual users, however, for the time being it is not so big of an issue as you would think. The cost of the download is filesize in GB (to 3 decimal places) * 0.1, then rounded down to 4 decimal places. It is the price of the torrent that identifies the payment, and unless two users simultaneously download a torrent of the EXACT same size, it is not an immediate problem. I plan to transition to a unique-address based solution soon.
With regards to the torrent status page, unfortunately, I cannot find a way to interface with the torrent client to update stats on realtime download speeds, ETA's etc. I can only differentiate torrent states, such as Downloading or Completed. I am working hard to try and improve the status page with more detailed information however.
Another good point you brought up with regards to multi-file torrents, with many subdirectories. I had considered doing exactly as you suggested and zipping up the whole torrent, but then I felt that some people may want instant streaming access to files contained within. I am still not decided on how I will proceed with this.
Torrent names, yep, again you are totally spot on. I intend to create folders with unique names in the future for downloads to prevent the exact scenario you suggested. Also, I don't really have a problem with multiple downloads of the same file as long as it does not start to become burdensome on the server. If this does become the case, I may have to put in place some further security layers to prevent this.
As for your speed, 400kb is indeed VERY slow. I don't understand how it could have been that bad. My website runs on a 100mbit dedicated server with unmetered bandwidth, based in europe. I max out my 30mbit home broadband connection downloading from this server every time, without fail. It could be due to the fact that the server is located so far away in europe, or maybe you just got it on a particularly congested time. It's hard to say. But I know that I am downloading something off it right now at a speed of 2.8 mb/s.
Thank you once again for your very in depth beta testing of the site and once again I really appreciate the time you took to write up this review that has provided me with such stimulating feedback.