There were patents floating around with other chains claiming ownership, that probably hindered adoption.

Interesting, as Wal-Mart hasn't followed this particular type of BS much in the past, they are one of the few places without loyalty cards (which prior data selling, were used by chains to look up customer history and decide whether a customer was profitable enough to bother with when they came to the customer service desk). They also in my past experience tending to have a very reasonable profit margin across goods. Not reasonable as in cheap, reasonable as in there are reasons when it is higher, like higher theft rate, spoilage, etc. They didn't seem to do loss-leaders and other such BS.

I've noticed Wal-Mart has been making unusually bad management decisions in the past year or so. Several stores seem to have changed their self checkouts and stopped manning them last winter with more cameras, but illegals seem to just forego pretense, walk up to the bagging station, bag their crap and walk out without ever presenting a credit card, making the cameras useless. They seem to have realized this and started manning the self checkouts again.

You may scoff, but in the past Wal-Mart rarely made mistakes like that, in the past they did lots of serious studies before rolling out sweeping changes like that.