After educating tan junkies about the chances of skin cancer, and how to use sunless tanning products, researchers discovered that these people were far more likely in the future to wear more protective clothes, and have fewer sunburns. These are both crucial factors in the prevention of skin cancer. By getting people hooked on the spray-on stuff, researchers prevented cancer and kept everybody looking like they'd been cooking in ultra-violet light.
The problem with this study, published in the Archives of Dermatology, is that it only compared the spray-on group to sunbathers who were a control group. They were not compared to people given the same information about skin cancers, but without the sunless tanning spiel, which might have proved sufficiently effective without dyeing people oompa loompa orange.
Research published in the Archives of Dermatology