2012 is nearing its end, and now's a good opportunity to look at what happened throughout the year to the stocks you follow. If you know the important things that a company achieved, as well as any challenges it failed to overcome, then you can make a better decision about whether it really deserves a spot in your portfolio.

Today, I'll look at StoneMor Partners (NYSE:STON). The company owns and operates cemeteries across the U.S., selling burial plots as well as caskets and other funeral-related services. Yet while that business has constant demand, the stock barely moved at all in 2012. What's behind the near-paralysis in the shares? Below, you'll find more to explain what happened with shares of StoneMor Partners this year.

Stats on StoneMor Partners

Year-to-Date Stock Return

0.7%

Market Cap

$420 million

Revenue, Past 12 Months

$242 million

Net Loss, Past 12 Months

($2.3 million)

1-Year Revenue Growth

7.4%

Dividend Yield

10.6%

CAPS Rating

****

Source: S&P Capital IQ.

Why was StoneMor Partners flat in 2012?
StoneMor is the second-largest cemetery owner in the U.S., with substantial land assets. Unlike its competitors, StoneMor is structured as a master limited partnership, allowing it to avoid corporate-level taxation and giving investors substantial distributions on their partnership units, much of which tends to be tax-free return of capital rather than taxable dividend income.

Of course, StoneMor isn't the only company in the industry. Carriage Services (NYSE:CSV) has recovered strongly from its financial-crisis plunge to give investors better-than-100% returns over the past year in the wake of some significant expansions, while Service Corp. International (NYSE:SCI) and Stewart Enterprises (NASDAQ:STEI) have also managed to produce good-sized gains in the industry. In addition to Matthews International (NASDAQ:MATW), every single one of these competitors has managed to earn a profit over the past 12 months, unlike StoneMor. Although accounting peculiarities affecting the funeral business may have something to do with the results, it still doesn't adequately explain why StoneMor stands apart from its peers.

In addition, the entire MLP structure has come under fire recently, putting StoneMor's advantage potentially at risk. With the fiscal cliff causing lawmakers to evaluate tax-reducing strategies unfavorably, some believe that Congress could eliminate MLPs' tax advantages, although the tax revenue raised would be minimal.

StoneMor hasn't given investors the performance they'd like to see in 2012. With the business getting more crowded, StoneMor needs to start executing more strongly in order to move forward more forcefully.

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Fool contributor Dan Caplinger has no positions in the stocks mentioned above. The Motley Fool owns shares of StoneMor Partners. Motley Fool newsletter services recommend StoneMor Partners. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.