Companies as diverse as Google, Microsoft, and are all trying to capture a part of the big data growth bonanza. Investors can profit from the high rate of growth in this arena by owning shares in the companies that provide the mission critical facilities.

Think of the merchants who sold tools and supplies during the gold rush -- they made money regardless of who struck it rich.

Data center REITs such as Digital Realty (NYSE:DLR) and CoreSite Realty (NYSE:COR) provide the bricks-and-mortar facilities and critical utility infrastructure for technology, health care, financial services, and e-commerce companies. This, in turn, allows those businesses to invest more time and capital into their core business initiatives. 

Here is a quick look at how each company has performed during the past 12 months compared to the S&P 500 and Vanguard REIT Index ETF (NYSEMKT:VNQ), a good proxy for all U.S. equity REITs.

                       DLR Total Return Price Chart

CoreSite Realty is the clear winner
But if you had to guess which of these two datacenter REITs has an investment grade debt rating, is significantly larger, has increased its dividend for nine straight years and pays a much higher yield -- you'd be wrong if you didn't guess Digital Realty. 

So, what happened to trigger the stock to drop over 20%?

The conference call analysts hated
Nobody likes to be blindsided, especially Wall Street analysts. Digital Realty CFO Bill Stein began his prepared remarks: "I will begin by discussing changes in our accounting policies, as well as new disclosures in our quarterly supplemental report." I am sure in retrospect there could have been better ways to present this information.

Digital Realty was not transparent.  Management neglected to mention accounting changes in the published earnings announcement. During the Q&A on the July 26, 2013 conference call, analysts jumped on the change of capitalizing operating repairs and maintenance, things that had previously been expensed. The change resulted in a $3.5 million boost to earnings for the first half of the year. Without the accounting change, Digital Realty would have had an earnings miss. 

Did anything fundamentally change?
There was discussion regarding the sales funnel, large customers taking more time to make decisions, and how that might result in revenue sliding into the next quarter -- but overall guidance was that Digital Reality is on track for the second half of 2013. 

However, some analysts are concerned that lease renewals for large datacenters may reflect lower pricing as they roll over. Based upon its sheer size -- 129 data centers in 10 countries -- Digital Realty might be more vulnerable to this trend than its smaller rivals. 

An opportunity for value investors

                         DLR Dividend Yield (TTM) Chart

Digital Realty is currently paying investors a dividend yield of almost 6%. Digital Realty had a $7 billion market cap and trades at a price to FFO ratio of only 10.9. 

Funds from operations, or FFO, is a measure of earnings commonly used by REITs where depreciation and some amortizations are added back to net income.

Next to competitors Dupont Fabros (NYSE: DFT), which has a market cap of $1.6 billion and a price to FFO ratio of 12.8, and CoreSite Realty, with a market cap of only $703 million sporting a price to FFO ratio of 18.2, Digital Realty appears to be "on sale" by comparison.

A significant margin of safety appears to be built into the current Digital Realty stock price.

CoreSite Realty continues to grow profitably
CoreSite supports 750 customers located in 2.5 million square feet in only 14 data centers. These facilities are located in eight of the top U.S. markets. CoreSite currently has three new data centers under construction and has the ability to nearly double its footprint utilizing land and buildings already owned.

CEO Thomas Ray discussing quarterly results stated: "...we aim to be a consistent company and just execute." He pointed out that "in Q2 we had very solid performance, with sales increasing 4% over Q1 and 14% over the prior year. We also had solid financial growth with 22% [year over year] growth in funds from operations, or FFO..."

CoreSite also edged its 2013 FFO guidance roughly 2% higher.

Investor takeaway
Digital Realty recently hired John Stewart as Senior V.P. of Investor Relations reporting to CFO Bill Stein. Mr. Stewart formerly led the industrial and technology REIT coverage at Green Street Advisors. Value investors get a margin of safety and a handsome dividend while waiting for Digital Realty to regain the confidence of Wall Street analysts and once again trade in line with its peers.

Growth investors can enjoy CoreSite Realty's high rate of profitable growth plus a dividend that has resulted in outstanding performance compared to both the S&P 500 and Vanguard REIT index ETF in total return.  

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.