Making buying SmarTrip/Transit passes more convenient

DC1974 sends us a link to this story from the Chicago Tribune, "Tollway board says grocer can collect $2.90 for transponder," and writes:

This is about tollways, but it reminded me -- why can't you buy SmartTrip cards in more places? There should be SmartTrip vending machines in Grocery and convenience stores. In SF, you could buy monthly passes all over town -- not quite the same thing. But it was convenient.----