I can see a legitimate need for that product (children with special needs, bruising disorders and so forth), but the extra padding for everyday children seems a bit much.
Something I keep meaning to mention is Cozy Beehive. Ron, the author of Cozy Beehive, is a mechanical engineer, avid cyclist, and a Category 4 racer. He's been blogging about bikes for a couple of years now but I first noticed Cozy Beehive a few months ago. I've bookmarked a whole pile of pages from his blog intending to link to them in posts here from Cyclelicious, but pretty much all of his posts are good so just go visit his blog and subscribe to his feed already.
To get 500,000 they must have used a fairly broad definition of "head injury". Probably the kinds of bumps and scrapes that every single one of us got when we were kids, right about the time that we (well, most of us) learned to stop smacking our heads into things. Shielding small children from that kind of feedback can severely restrict their ability to learn how to interact with their environment.