A recent play-though has led me to think it may be worth leaving the remaining countries in your home continent without satellites (excluding South America).
If you have 2 or more countries without satellites you continue to get Abduction missions. You still get your continent bonus but the extra cash, meld and rewards from Abduction missions are a decent boost to you mid game.
As you are only completing abduction missions in one continent the panic doesn't rise either.
That is assuming they don't replace normal UFO missions – does anyone know whether this is the case or not?
Edited: to state mid game rather than early game as rightly pointed out.
Best Answer
Having played through 2 classic games now I'm pretty happy that this is a sound strategy.
You do get extra abduction missions and the extra cash & weapon fragments mid-game do help a lot. Also abduction missions tend to be some of the easier missions and so are good for levelling up your troops.
I have not yet tried this on Impossible.