Product review (5 stars): Yep, they work!
As someone with four cats, I'm too familiar with the sound of the "hairball hack."  I've tried cat lax and food that claimed to reduce or prevent hairballs all to no avail.  I have one cat that I could count on hacking up her food at least 3-4 times a week and another occasional puker.  To be honest, I wasn't all that convinced these treats would work but figured it was worth a shot.
Well, wouldn't you know it- they actually work!  In the month and a half that I've been giving these treats, there has been TWO hairball events.  Woo-hoo.  I've shared these with a friend who just told me today they've worked miracles for her two cats.
It may not prevent all hairballs but let's be honest- anything that reduces the chance of stepping in a cold, wet hairball is well worth the money.