put.io is a hosted/cloud based torrent downloader/client.
To put things simple, what it does is: It downloads torrents for you on their server using their bandwidth. And once the downloading is finished at their server, you can then download the file to your computer using your ISP bandwidth.
If you regularly download old movies with torrents, you know how frustrating it is to wait for seeds for days. Torrent stuck at 98% for days, might be a thing we all have experienced. But with put.io, as things are being first downloaded on their server, you dont have to be bothered with that. No more keeping computer on days just to finish that torrent.
The put.io paid accounts come with 15 concurrent torrent downloads. So you can easily put some old hard-to-find-seed torrents on their server and let it rest there. And once the download is completed there (yeyy!), you can download the file to your computer. Thus, at your end, you are just downloading the file.
And if its a popular torrent, you are most likely to experience a instant download on the server. This happens as put.io has grown up to be a “torrent network” itself. So, if there are other users downloading that torrent, the transfer is just a super fast local transfer. This is why i prefer using put.io over a torrent flux on my own server.
I have been using put.io for months now. Even though its now paid only, I consider the money well spent.