I've never played it on Wifi. I've know a couple players who do though, but it's only if they have no one to play with in person.
I play at least once a week myself, usually me and a few friends play. If not, I'll at least practice against computer.
I'm trying to improve so I can do better in tournament play. There's only a few tournaments a year in my state though, so it's hard to stay motivated having to wait 3-4 months for the next one to come around.