I'd be the first to admit that this has a fairly small target audience out their in piland, but I'll toss it in for the few who may find it useful. It has merit in 3 areas, you can use one less usb port, you can configure wireless net of any gui (of a keyboard either even), and if you run OSMC, its far more stable.
You need to have an 'old' Sky wireless adapter - the one they are giving away willy-nilly to every subscriber with a digi-box that does not have built-in wifi. I upgraded my box to one that does and thus the adapter was just lying around. (maybe you have one but don't use it as it sooks bandwidth for fun sometimes).
Anyhoo, the clever bit is that you just plug it into the pi's ethernet port and (DHCP from your router willing) the pi 'thinks' eth0 has come up - even though its a wireless attachment. Now, apologies for this bit, (but I'm lazy) life is much easier if you configure the adapter itself to connect via you router by attaching it to the sky box - easy because its a few clicks on the sky remote, after which you can just stick it straight into the pi Ethernet port and away you go. Another advantage (again, only if you have one) is it saves you moving wifi dongles between pi's!
For me, my wifi connection via a donlge kept dropping off using OSMC, but when it thinks eth0 is up it rock solid.
Lastly, (and you can have a bit of fun with this I'd think if you are so inclined), you can hit the reset button on the dogle and try set it up 'properly' via the linux commnad line. (but i'm err a tad lazy for that, leave to the pengurus)