I'm still riding on a multi-year supporter account, and I snagged it for two reasons initially: a custom title and the search feature.
I'll keep it up in the future whenever it expires, but had you asked me a year ago I might not have said the same. I had a lull in visiting and posting here around when 4e came out, both from being sincerely jaded over the edition and its marketing, and what I felt at the time was a bit too much overt support for 4e by the site itself, the domination of the front page by WotC stuff, the barrage of WotC banner ads, and the almost poisonous atmosphere if you didn't treat it like the second coming (whereas I viewed it as less Messiah and more Bar Kochba).
However it's gotten better, I still prefer to get RPG related news and discussion here, and moderation has kept the worst of the edition warriors in check. The DDI potpourri in General is sometimes a bit much, but lately some overtly Rules stuff has been nipped in the bud, so that's been better as well.
End result: it's a seriously minor expense given how much time I'm here lurking, and I'll happily support the place given how long I've been here.