Self-regulation tends to crop up not out of altruism or doing the right thing, but rather as a means to forestall legislative regulatory efforts which in turn would prove to be more damaging to sales.
Take this recent initiative out of Australia which will see the food industry not advertising their junk to kids within 150m (500ft) of schools. 150 whole metres! While certainly not likely to do anything at all, it'll be especially useless perhaps in that the school buses themselves will be exempt, as of course will be the bus stops' shelters.
Oh, and as toothless as it is, it's also voluntary.
Really the only thing this initiative will do is provide the food industry with ammunition if and when facing calls for legislated regulation (something we're hearing more and more calls for) and to pretend that they care about anything other than profits.
It's always best to remember, as I've written before, the food industry is neither friend, nor foe, nor partner.