We've been working the 4-day work week far longer than we've had VC money. Our first investment came in the fall of 2011, long after we existed as a company, and we were profitable prior to raising VC.
Our support team also works a bit on the weekend (around 3 hours per day), and that's something we're working on fixing by adding to the team.
In general I don't think people on our team work more than 32-35 hours or so. One exception is our support team, and that's something we're working on remedying.
In general I saw that developers working on "a secret sauce" (i.e., engineers in Oracle working on RDBMS, etc.) are not working more than 35 hours a week while developers working on some generic CRUD crap work all days and night.
Now the challenge is to hire developers which can work on or develop your "secret sauce"... which is point of this post.
As I understand it, Henry Ford chose a 40-hour work week because he found that it maximized the total output of his employees. Computer programming is (minute-for-minute) considerably more demanding than working an assembly line. Maybe an average programmer maximizes her total output when she works substantially less than 40 hours a week. In fact I'd be surprised if that weren't the case.
And of course you could still run the service if you guys worked four-day weeks. Just make sure somebody's working on any given day.
Hacking code may be more mentally taxing, but if you need to take break (for the bathroom or whatever) you can do it on your own schedule -- not on your lunch break like a lot of factory workers.
Look, I know little about Treehouse, but I read the blog when things appear on HN. It looks like a useful product, and seems to be run by sincere guys. But you're talking about attracting good talent when you're able to offer amazing benefits, salaries and a 4 day work week. That is only possible because you're swimming in cash, and you're only swimming in cash because this space is still riding the upswing of the business cycle. The market will sort this out, and one only has to look around to see that. It's unsustainable. How old is your business? Let's see if you're still working 4 day weeks in five years.
That said, it's probably a great place to work. Kudos for sharing the wealth with your employees.
I'd say that's pretty good proof that it's not just sustainable, it's also very smart.
You started a business in 2007 using a 4 day work week and it was acquired in 2008? That's not evidence of sustainability. Smart? Yes, apparently. But is that business still using a 4 day week?
Yes, the acquired company still runs a 4-day week.