To be honest for a company to provide you free seedbox is a not a sustainable option because server space and high bandwidth both cost , In internet if you search for free seedbox you might most probably run into some scammy company running some kind of survey or make you download some malicious toolbar software , THEY NEVER PROVIDE SEEDBOXES.
The only genuine company that does give you free seedbox is pulsed media, pulsed media has been in business for quite sometime , but they done give it to you instantly they have a lot of free slots and once you register they give one to you as soon as a slot becomes free.
Visit Pulsed Media Link- Click Here
They they do provide free seedbox , I would definitely recommend you to get their trial seedboxes which will help you understand how a seedbox works and whether or not you really need it, pulsedmedia also has one of the cheapest seedboxes with the best servers, so you can also take a look at their very cheap 1mps and 1gbps seedboxes
