Why snow-covered?

[jakjakman]

Hey there, yes it's my first post.  I've been away from Magic for several years, and I'm now getting back into Vintage. Yay!  So after reading up on all the new tech out there, I still don't know why some decks run a single snow-covered land.  What does the snow-covered land do for you?

[Prometheon]

Snow Covered Lands have a different name than non-snow covered ones, but are still basic, giving you more options with Gifts Ungiven. There is no loss of cutting 1 Island for 1 Snow-covered Island, and you get a tiny increase in lines of play in the face of heavy mana denial.

Edit: Some people will say that the tiny increase is not worth it, as if an opponent sees a Snow Covered Island, they will immediately put you on Gifts and be more prepared to disrupt your gameplan. Reverse psychology works wonders here, as you can throw Snow Covered Islands into decks like Fish and Slaver to give your opponent false signals.

[jakjakman]

Ah, now I see.  Thanks!