True, although it’s a little more complicated than this, as Banquet Bear’s links make clear.
In the United States, you can make money from a picture without a model release. You can sell your photos to whomever you like, for as much money as they are willing to pay, and a model release isn’t necessary. A model release relates not to the taking of a picture, but to the publication of a picture. And even then, there are plenty of ways that you can publish a picture without a release.
For example, using an image for news, artistic, or editorial purposes does not require a release. If you take a picture of someone at a rally, or at the scene of an accident, or at a sporting fixture, and your local newspaper asks if they can use your picture to run alongside a story about the event, no model release is necessary for the publication of this image. It’s a news story, and the use of the image is for news or editorial purposes. And this is true even if the paper pays you money for the image.
If, however, you want to publish a picture in a setting that is designed to endorse a particular product or service or organization, and if there are recognizable people in the image, then a release is generally necessary. The most obvious example is pictures used to illustrate advertisements, but there are other instances as well.
It’s worth noting, though, that the responsibility for obtaining the model release (legally, at least) falls on the publisher of the photo, NOT on the person who took the photo. So, if a company calls you up and asks if they can buy a picture that you took of a group of people, you can sell it to them. If the company then goes and uses that picture in an advertisement for its products, then the company is the one who has fucked up, and could face a lawsuit.
But companies know this, and so most companies that buy images for commercial purposes (including stock photo agencies) usually require, before purchasing the image, that the photographer secure model releases for any identifiable people within the photos. Commercial photographers obtain model releases for all their images as a matter of course, wherever possible, if they want to sell those photos to stock agencies or advertising agencies or other outlets that use images for explicitly promotional purposes.
Basically, for 99 percent of photographers who are taking pictures for their own personal enjoyment, or for artistic purposes, or for news purposes, or even to publish a book of photos, a model release is basically never required. The OP will be fine without them.
Leo Krupe, when you are looking for photography gear, if you want to get a decent amount of bang for your buck, i highly recommend the Buy/Sell section of the Fred Miranda photography forums. Members of this forum buy and sell gear on a regular basis, and as long as you’re a little bit careful, and check people’s feedback, you can get some excellent deals.
My last four purchases of photographic gear have all been done through Fred Miranda, and i’ve purchased some outstanding used equipment in excellent condition, at well below the sort of prices you’ll find in stores. I got my Nikon D7200 with extra battery grip for a little over $600, and just a week ago i took delivery of a like-new Nikon 16-80/f2.8-4 lens for $560 (new price: $1066). I’ve also bought a couple of different flash units there - an SB-700 on-camera flash, and a set of two R1 wireless close-up flashes for mounting on my macro lens. It’s now my go-to place when i’m looking for “new” (used) equipment.
Note: I have no affiliation with the site; i’ve just used it to get some good deals on camera equipment.