Yes, but mostly to get the achievements. I never even tried the >2 player multiplayer game, because it just seems to take too long. Especially since the cards you can choose from are so sparce, once anyone can use any recommended deck on any homepage. It's quite different from buying cards in real life, because anyone can have any card (except for premiums, which you need to play or pay for), so there might be a point where you say "okay, he has deck X, I have Y, I will lose, concede", because it is obviout that you might lose.
So in the end, I didn't even bother online, at all. I just played for cards offline and achievements.