Coinstar (NASDAQ:CSTR) has a way with words. It's looking to increase the profitability of "the fourth wall" and, by doing so, plant its coin-gobbling machines in well-frequented stores. Most of us probably hadn't guessed that the "fourth wall" had some kind of a problem to begin with.

At any rate, you might already know that Coinstar reported fourth-quarter earnings last week. Net income was $4.6 million, or $0.20 per share. Excluding charges, earnings were $0.26 per share. Fourth-quarter revenue doubled to $109.8 million.

Meanwhile, Coinstar lowered its estimate for the first quarter, to $0.14-$0.21 per share, or, adjusted, to $0.17-$0.24 per share. Consensus estimates were expecting first-quarter earnings of $0.26 per share.

All right, back to the "fourth wall" stuff. In its conference call, company representatives said some interesting things about Coinstar's growth plans. With consumer spending increasingly focused on store perimeters, as opposed to the center of a store, Coinstar said it's looking toward making that "fourth wall" -- the front of the store, when you envision your local supermarket -- a more profitable place as opposed to a neglected strip of in-store real estate.

"We went from being a one-trick pony to a multidimensional business," management said in the call, referring in particular to its acquisition of American Coin Merchandising (ACMI) as a "transformational event."

ACMI, if you recall, was the company that specialized in vending and crane games that appear in the front of supermarkets, drugstores, and the like. Meanwhile, Coinstar is also dabbling in some e-payment schemes and recently ran a pilot program in 3 cities in which its coin machines also distributed payment cards for retailers like Starbucks (NASDAQ:SBUX), without charging the usual fee for coin counting.

Basically, Coinstar's mission is not only to turn people's spare change into cash (and take a bite out of the proceeds when it does), but also to increase the profitability of those front walls in the stores. Indeed, anybody who's been to a supermarket that harbors a Coinstar machine knows that the front of the store is where the machine resides -- as do the gumball machines and skill cranes that ACMI brought to the table.

Meanwhile, Coinstar gave a rather subdued view of the first quarter, giving investors something to be leery about. In November, right here at the Fool, contributor Marko Djuranovic questioned the stock's valuation compared to its projected growth trajectory.

Indeed, given recent signals that Coinstar might be having some growing pains, a price-to-earnings ratio of 25 sounds a bit steep for any investors who are interested in buying this stock. And all the talk of the "fourth wall" made me wonder whether the basis of its business needs a big infusion of something to jump-start growth. Meanwhile, the thought of it having once been a "one-trick pony" makes me wonder if that pony's getting a little lame -- or if its acquisition is in need of justification.

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Alyce Lomax does not own shares of any of the companies mentioned.