Warm moist conditions favor the growth of more than greens.
I wonder how rigorous the supermarket procedures have to be to keep this set-up from growing nasty things.
Having said that, I do think its safer this way than the traditional distribution method and has the added benefit of longer shelf-life, since the greens don't spend a week or two between picking and the eventual sale.
ETA...Looking at their website, they grow mostly herbs as opposed to what would make up the body of a salad. There are a couple salad greens for sure, but I infer that they can't grow bulk greens on a practical scale yet.
