Imp. Ghost WolfFollow

I am leveling an Enhancement Shaman. All the specs I have seen for Enhancement have Imp. Ghost Wolf. I, being new to Shaman, am not really sure why that would make much of a difference. I understand I need 2 points in something to get to the next tier, I am just not sure why I should put it in that when I could put it in to anticipation or imp lightning shield. Can anyone enlighten me on why Imp. GW is important?

Basically it's not good in PVE but it's one of our only movement-enhancing options in PVP. So skip it if you don't PVP (although your other options aren't fantastic, at least they'll increase survivability.)

Why would you PVP as Enhancement? I don't know, but mysteriously I far out-damaged and out-KBed my team as Enhancement in one AV where the opposing team strangely refused to focus fire/CC me. So I've upgraded my opinion from "horribly bad in all forms of PVP" to "horribly bad unless nobody targets you".

For dungeon/raid PVE it's almost entirely useless due to almost no PVE content being outdoors.

For questing/leveling it's fairly useful.