Sky Go Extra + Multiscreen = new 12 month subscription?

Apologies if this is covered elsewhere - I did do a search but couldn't find it.

I just found out that as a multiscreen customer I can have Sky Go Extra at no monthly fee.

However, the initial screen has this little gem: "12 months minimum subscriptions apply."

So my question is - if I were to activate the free subscription (laughable considering the cost of everything!), do I enter into a new 12-month contract for either the package/Go Extra or both?

Cheers.