Walmart has been on a path to become more innovative by expanding into tech: online, clean energy, and robotics, I'm sure I'm missing some more. They know they aren't at heart a tech company and leave it to others. They do invest, team up, or both. If it proves beneficial to them they expand on it. They realize that they need to compete with Amazon and tech is a good way to do that. Regarding Plug, that's for the fork lifts. Walmart is looking into floor cleaning bots now. Imagine, a fuel cell floor cleaning bit where the exhaust is used to clean and the waste water is drained onto HYSR cells to produce hydrogen and maybe break down to waste to a more gentler kind ND maybe even get some useful chemicals from it. I wouldn't put too much stock in it but don't underestimate Wal-Mart.