I am out of town, writing this from the usual orange & brass decorated hotel room. Like a lot of writers I need a day job--and at the moment I need a new job because my current position is coming to an end. Thus the out-of-town job interview, thus the hotel room. Nevertheless I am dropping in with my self-POD thought for the day. It comes from Tessa Gerritsen's blog.
Tessa reminds us that most book stores not only will not, but cannot, stock self-POD books. And this is something that all self-POD authors should know in advance to avoid throwing embarrassing little hissy fits in store like the author described in her post.
One issue is the one mentioned. Bookstores will only shelve books that are returnable. And not returnable only within a few months--returnable for a full refund at any time. Another relevant issue is discount. Most chains expect around 50% and as much as 60% and the economics of POD don't lend themselves to that.
Local stores may be more supportive especially if you provide books on consignment, but currently routine stocking in mainstream chain bookstores is just not the name of the game.