I wouldn't be surprised if the average was 10-20% and a vast majority of these people are taking advantage of what they see as a good deal irregardless of their feelings on holacracy as a management style.
Here's an article from 2008.
tl;dr is "If you quit today, we will pay you for the amount of time you’ve worked, plus we will offer you a $1,000 bonus."
Paying you for the amount of time you worked is a legal obligation. So really you are talking about can you find an equivalent or better job in the amount of time you would have earned $1,000 if you stayed. Even in the lowest of paying legal jobs in the US, it does not take that long to earn $1,000 relative to securing a job. Not to mention that new job is not guaranteed to fit into your current living situation and other factors that cause the inertia for staying with a current job to be quite large. Seems a bit like a gimmick to me.
It's a sales job, with you as the product.
I. Hate. Doing it.
So while a lot of people could go out and get a better, higher-paying job, there is a potential barrier and significant activation energy for that reaction. Doing my regular job plus the self-sales job is absolutely exhausting.
When my current job is already almost good enough to keep, I have little incentive to go sift through piles of recruiter spam and speculative postings to find the actual jobs, retype every last detail of my resume into yet another stupid custom candidate tracker web-app, suffer through the bozo filter and the pop quiz of the tech screen, fly or drive wherever, and spend one of my vacation days playing along with some stupidly involved interview process, only to see a curtain of silence descend forever.
For $30k, and an extra 40 hours per week in which to do it, I would certainly put up with the tech hiring circus for a couple of months.
Technically you'd come out positive if you found something that's at least more than (what you make) - 30k, but then you have to consider raises and such.
If you consciously attempt to hire true believers, then you will get two kinds of employees: true believers, and people who lie about true believers.
That set of employees is probably pretty small compared to the larger set of qualified employees without such a restriction. You write off a huge pool of talent.
Just because you're a mercenary doesn't mean you won't bring your all to the task at hand.
Also, consider the employee relationship from the other direction. No corporation is going to hire an employee because the corporation is a true believer in the employee's mission. That relationship is a strictly mercenary one: Can you do for us what we need you to do for us?
Full disclosure: I'm old.
Even if your anticipated time between jobs is 1-2 months, you can still confidently quit by the deadline and end up with six weeks paid vacation and a six weeks bonus.
Extend things to 1-2 months and that probably drops to 20% or so which is very good odds.
However, the difference between a 'competitive' offer and a 'good' one at a company you want to work for is huge. If your spending between 1/3 and 2/3 of your waking hours at work you need to make them count.
It's not even so much about the vacation being paid but having certainty. I haven't changed jobs a lot but the last time was pretty typical: get an offer and then "when can you start?" I ended up taking a 2-3 week vacation arranged on about 3 weeks notice.
The ones that are confident they could land another better job by the quit date.
It's not enough to be possible to get any job. The offer only makes sense if you are certain you will trade up.
And it does not have to be a better job, it could be even one that pays less. If the person needed cash fast, this is one way of getting it. They could spread those losses over a year. It's still better than a payday loan.
If I'm happy, I'm not quitting even though I could easily get another job. It's not always about the money.
Zappos is located in Vegas, which is a bit of an oddball market and somewhere between these poles I would think.