In the case of Hurricane Electric, I think this has also been a marketing/evangelism/thought leadership activity on their part. They're the experts I think of w

In the case of Hurricane Electric, I think this has also been a marketing/evangelism/thought leadership activity on their part. They're the experts I think of when I think about IPv6, largely because they've been doing this for a long time and they have clueful people working for them, in addition to the fact that they provide free tunnels.