I work for a Boulder tech startup with an unlimited vacation policy.

Last year I took a month in Japan and South Korea, I just returned from two weeks in Tokyo, Taipei and Hong Kong. I also spent two weeks in Europe earlier this year, plus some odd long weekends and a planned week away around Christmas. I think my total for 2014 comes to around six weeks.

We also have a policy of working one month a year remotely from anywhere and the company pays part of the expense. I'm heading to Hanoi next year to take advantage of that. Our CEO/co-founder took his family to Australia for a month.

An exception? Probably. But it works for us.

It is compared to a "long weekend" as described in the parent comment. Although it would be nice, taking a month off every year would be grail-status vacation time for a US employee I think.

Also, I don't work in Silicon Valley.