The problem with non-powered hubs is that, they lack a lot of uses. With this hub, all 7 devices would have to share the same power as 1 USB device, this would mean that many devices are unsuitable and it would just keep disconnecting the devices if this occurs.
So it depends what you will use it for, like a keyboard and mouse might be fine, but just remember that if one device tries to consume to much power that both would disconnect. This can be very problematic and for this reason I would not recommend plugging in either of those especially if you are intending of playing games or something which lack of mouse / keyboard functionally would affect.
So that brings me on to say "what is it useful for?", well anything which uses a small amount of power, most of the time these are things which have an included external power. Something which does not require any power to be required. Or maybe a couple of USB flash drives (however due to the disconnection of power, I would not recommend it).
Something which I say is that do not be surprised if you have issues, I believe as above it would work fine on anything which is externally powered or something which does not consume a lot of power. But just use it for devices which are not the end of the world if they go off. Also plugging in more than 2 or 3 devices maybe cause a problem.
So if you do need a hub, I would recommend getting a powered hub, this eliminates these issues. Although I would still recommend connecting mouse / keyboard directly into your computer, but a powered hub can easily power USB hard drives, USB flash drives. So just keep that in mind.