metta8 saidI have heard that their memberships are cheap. And I would guess that their goal is to maximize profits, not get people healthy. One goal is probably to get more members to pay dues that don't actually go to the gym. And many of the ones that do go probably go so they can tell their friends that they workout and possibly make them feel ok about the way that they eat. "Well, I worked out today so that makes it ok for me to eat a pie." ;)
If people don't use the machines as much as they do in other gyms then they probably don't need to repair them as often either. That probably saves them money as well.
eagermuscle saidI know the manager of a Planet Fitness. He says some members only come in for the free pizza and don't even bother working out. Though it's a chain with perceived uniformity some branches - often those in which Planet Fitness is the only game in town - have a more upscale serious clientele and forgiving management. Say what you will but most fat people are too intimidated or shy to go to a regular gym, so anything that gets them on a treadmill for five minutes can't be bad. As for how they stay in business discouraging fit people and offering such low rates it's the typical business model that relies on absentee members being continually auto-debited. The cheaper the membership, the less the member minds being billed for being a no-show. Brilliant strategy actually, even taking into account those that just show up to eat $10 worth of free pizza.
Although I've been critical of PF's judgmental attitude toward people who care about health and fitness, there are some good things.
PF is also the only place you'll see guys in their 80s, people in wheelchairs, and
a surprising number of men and women who are in seriously great shape working out together.
As EM suggests, you'll also see seriously obese people. All of the above benefit from working out, and they may not be willing to do it anywhere else.